3408C & 3412C MARINE ENGINES Caterpillar


Systems Operation Testing & Adjusting

Usage:

Systems Operation

Engine Design

3408C


Cylinder, Valve And Injection Pump Location

Number And Arrangement Of Cylinders ... 65 degree V-8

Valves Per Cylinder ... 4

Displacement ... 18.0 liters (1099 cu in)

Bore ... 137.2 mm (5.40 in)

Stroke ... 152.4 mm (6.00 in)

Compression Ratio ... 14.5:1

Type Of Combustion ... Direct Injection

Direction Of Crankshaft Rotation (as viewed from flywheel end) ... Counterclockwise

Direction Of Fuel Pump Camshaft Rotation (as viewed from pump drive end) ... Counterclockwise

Firing Order (Injection Sequence) ... 1-8-4-3-6-5-7-2

Valve Lash Setting

Inlet ... 0.38 mm (.015 in)

Exhaust ... 0.76 mm (.030 in)

NOTE: Front end of engine is opposite the flywheel end. Left side and right side of engine are as viewed from the flywheel end. No. 1 cylinder is the front cylinder on the left side. No. 2 cylinder is the front cylinder on the right side.

3412C


Cylinder, Valve And Injection Pump Location

Number And Arrangement Of Cylinders ... 65 degree V-12

Valves Per Cylinder ... 4

Displacement ... 27.0 liters (1649 cu in)

Bore ... 137.2 mm (5.40 in)

Stroke ... 152.4 mm (6.00 in)

Compression Ratio ... 14.5:1

Type Of Combustion ... Direct Injection

Direction Of Crankshaft Rotation (as viewed from flywheel end) ... Counterclockwise

Direction Of Fuel Pump Camshaft Rotation (as viewed from pump drive end) ... Counterclockwise

Firing Order (Injection Sequence) ... 1-4-9-8-5-2-11-10-3-6-7-12

Valve Lash Setting

Inlet ... 0.38 mm (.015 in)

Exhaust ... 0.76 mm (.030 in)

NOTE: Front end of engine is opposite the flywheel end. Left side and right side of engine are as viewed from the flywheel end. No. 1 cylinder is the front cylinder on the left side. No. 2 cylinder is the front cylinder on the right side.

Fuel System



Fuel System Schematic

(1) Fuel tank.
(2) Tank shutoff valve.
(3) Fuel injection nozzle.
(4) Fuel manifolds.
(5) Fuel injection pump housing.
(6) Bleed orifice.
(7) Fuel inlet line (from secondary filters).
(8) Fuel inlet line (from primary filter).
(9) Check valve.
(10) Fuel transfer pump.
(11) Secondary fuel filter.
(12) Primary fuel filter.
(13) Fuel priming pump.
(14) Fuel transfer pump relief valve.

There is one fuel injection pump and one fuel injection nozzle for each cylinder. The fuel injection pumps are located in the fuel injection pump housing. The fuel injection nozzles (3) are located in the injection adapter in the cylinder head.

When the engine is running, fuel is pulled from the fuel tank through the fuel supply line and primary fuel filter (12) by fuel transfer pump (10). The fuel is then pushed to secondary fuel filters (11), and into the fuel filter housing. A bleed orifice (6) in the fuel filter housing cover vents air in the system through a line back to fuel tank (1). Fuel from the fuel filter housing goes through fuel inlet line (7) to fuel manifolds (4) in fuel injection pump housing (5). The fuel manifolds supply fuel to each fuel injection pump.

Individual fuel injection lines carry fuel from the fuel injection pumps to each cylinder. One section line connects between the fuel injection pump and an adapter on the valve cover base. Another section of line on the inside of the valve cover base connects between the adapter and the fuel injection nozzle (3).

The fuel filters and priming pump are located in a compartment at the front of the fuel tank. The fuel transfer pump is mounted on a drive adapter on the fuel injection pump housing, and is driven by a shaft connected to the fuel injection pump camshaft. Fuel transfer pump relief valve (14) is located in the cover of the pump.

Fuel priming pump (13) is used before the engine is started to put pressure in the fuel system and to vent air from the system. A check valve (9) located in the fuel transfer pump adapter housing will let fuel go around the fuel transfer pump when the priming pump is in use.

There is no bleed orifice or valve installed on the fuel injection pump housing to vent air from this part of the fuel system. Air trapped in the fuel injection lines can be vented by loosening all of the fuel injection line nuts where they connect to the adapters in the valve cover base. Move the governor lever to the low idle position. Crank the engine with the starting motor until fuel without air comes from the fuel line connections. Tighten the fuel line nuts. This procedure is necessary because the fuel priming pump will not give enough pressure to push fuel through the reverse flow check valves in the fuel injection pumps of a direct injection system.

An automatic timing advance unit is mounted on the front of the fuel injection pump camshaft. It is driven by the engine camshaft gear inside the front timing gear housing. The automatic timing advance unit gives easier starting and smooth low speed operation. It will also advance timing as engine speed increases to give correct engine operation efficiency.

Fuel Injection Pump



Cross Section Of The Fuel Injection Pump Housing

(1) Fuel manifold.
(2) Inlet passage.
(3) Check valve.
(4) Pressure relief passage.
(5) Pump plunger.
(6) Spring.
(7) Gear.
(8) Fuel rack (left).
(9) Lifter.
(10) Link.
(11) Lever.
(12) Camshaft.

The rotation of the lobes on the camshaft (12) cause lifters (9) and pump plungers (5) to move up and down. The stroke of each pump plunger is always the same. The force of springs (6) hold lifters (9) against the cams of the camshaft.

The pump housing is a "V" shape (similar to the engine cylinder block). The 3408C has four pumps on each side and the 3412C has six pumps on each side.

When the pump plunger is down, fuel from fuel manifold (1) goes through inlet passage (2) and fills the chamber above pump plunger (5). As the plunger moves up it closes the inlet passage.

The pressure of the fuel in the chamber above the plunger increases until it is high enough to cause check valve (3) to open. Fuel under high pressure flows out of the check valve, through the fuel line to the injection valve, until the inlet passage opens into pressure relief passage (4) in the plunger. The pressure in the chamber decreases and check valve (3) closes.

The longer inlet passage (2) is closed, the larger the amount of fuel which will be forced through check valve (3). The period for which the inlet passage is closed is controlled by pressure relief passage (4). The design of the passage makes it possible to change the inlet passage closed time by rotation of the plunger. When the governor moves fuel racks (8), they move gears (7) that are fastened to pump plungers (5). This causes a rotation of the plungers.

The governor is connected to the left rack. The spring load on lever (11) removes the play between the racks and link (10). The fuel racks are connected by link (10). They move in opposite directions (when one rack moves in, the other rack moves out).

Fuel Injection Nozzles

The fuel injection nozzle is installed in an adapter in the cylinder head and is extended into the combustion chamber. The fuel injection pump sends fuel with high pressure to the fuel injection nozzle where the fuel is made into a fine spray for good combustion.



Fuel Injection Nozzle

(1) Carbon dam.
(2) Seal.
(3) Passage.
(4) Filter screen.
(5) Inlet passage.
(6) Orifice.
(7) Valve.
(8) Diameter.
(9) Spring.

Seal (2) goes against the nozzle adapter and prevents leakage of compression from the cylinder. Carbon dam (1) keeps carbon out of the bore in the nozzle adapter.

Fuel with high pressure from the fuel injection pump goes into inlet passage (5). Fuel then goes through filter screen (4) and into passage (3) to the area below diameter (8) of valve (7). When the pressure of the fuel that pushes against diameter (8) becomes greater than the force of spring (9), valve (7) lifts up. This occurs when the fuel pressure goes above the Valve Opening Pressure of the fuel injection nozzle. When valve (7) lifts, the tip of the valve comes off of the nozzle seat and the fuel will go through the six small orifices (6) into the combustion chamber.

The injection of fuel continues until the pressure of fuel against diameter (8) becomes less than the force of spring (9). With less pressure against diameter (8), spring (9) pushes valve (7) against the nozzle seat and stops the flow of fuel to the combustion chamber.

The fuel injection nozzle can not be disassembled and no adjustments can be made.

Hydra-Mechanical Governor

The throttle lever, or governor control, is connected to the control lever on the engine governor. The governor then controls the amount of fuel needed to keep the desired engine rpm at the throttle lever setting.



Hydra-Mechanical Governor

(1) Collar.
(2) Bolt.
(3) Lever assembly.
(4) Upper spring seat.
(5) Governor weights.
(6) Governor spring.
(7) Lower spring seat.
(8) Thrust bearing.
(9) Valve.
(10) Upper oil passage (in piston).
(11) Piston.
(12) Lower oil passage (in piston).
(13) Sleeve.
(14) Oil passage (in cylinder).
(15) Drive assembly.
(16) Cylinder.
(17) Pin.
(18) Lever.

The governor has governor weights (5) driven by the engine through the drive assembly (15). The governor has a governor spring (6), valve (9) and piston (11). The valve and piston are connected to one fuel rack through pin (17) and lever (18). The pressure oil for the governor comes from the governor oil pump, on top of the injection pump housing.

The oil used is from the engine lubrication system. Pressure oil goes through oil passage (14) and around sleeve (13). The throttle lever, or governor control, controls only the compression of governor spring (6). Compression of the spring always pushes down to give more fuel to the engine. The centrifugal force of governor weights (5) always pulls to get a reduction of fuel to the engine. When these two forces are in balance, the engine runs at the desired rpm (governed rpm).

The governor valve (9) is shown in the position when the force of the governor weights and the force of the governor spring are in balance.

When the engine load increases, the engine rpm decreases and the rotation of governor weights (5) will get slower. (The governor weights will move toward each other). Governor spring (6) moves valve (9) down. This lets the oil flow from the lower oil passage (12) around the valve (9) and through the upper oil passage (10) to fill the chamber behind piston (11). This pressure oil pushes the piston (11) and pin (17) down to give more fuel to the engine. (The upper end of the valve stops the oil flow through the top of the piston, around the valve). Engine rpm goes up until the rotation of the governor weights is fast enough to be in balance with the force of the governor spring.

When there is a reduction in engine load, there will be an increase in engine rpm and the rotation of governor weights (5) will get faster. This will move valve (9) up. This stops oil flow from the lower oil passage (12), and oil pressure above piston (11) goes out through the top, around valve (9). Now, the pressure between the sleeve (13) and piston (11) pushes the piston and pin (17) up. This causes a reduction in the amount of fuel to the engine. Engine rpm goes down until the centrifugal force (rotation) of the governor weights is in balance with the force of the governor spring. When these two forces are in balance, the engine will run at the desired rpm (governed rpm).

When engine rpm is at Low Idle, a spring-loaded plunger in lever assembly (3) comes in contact with a shoulder on the adjustment screw for low idle. To stop the engine, push throttle lever to vertical position. This will let the spring-loaded plunger move over the shoulder on the low idle adjustment screw and move the fuel rack to the fuel closed position. With no fuel to the engine cylinders, the engine will stop.

The governor oil pump supplies oil to the valve (9) to increase governor power and response. Oil from the governor oil pump gives lubrication to the governor weight support (with gear), thrust bearing (8), and drive gear bearing. The other parts of the governor get lubrication from "splash-lubrication" (oil thrown by other parts). Oil from the governor runs down into the housing for the fuel injection pumps.

Automatic Timing Advance Unit



Automatic Timing Advance Unit

(1) Flange.
(2) Weight.
(3) Springs.
(4) Slide.
(5) Drive gear.
(6) Camshaft.

The automatic timing advance unit is installed on the front of the camshaft (6) for the fuel injection pump and is gear driven through the timing gears. The drive gear (5) for the fuel injection pump is connected to camshaft (6) through a system of weights (2), springs (3), slides (4) and flange (1). Each one of the two slides (4) is held on drive gear (5) by a pin. The two weights (2) can move in guides inside flange (1) and over slides (4), but the notch for the slide in each weight is at an angle with the guides for the weight in the flange. As centrifugal force (rotation) moves the weight away from the center, against springs (3), the guides in the flange and the slides on the gear make the flange turn a small amount in relation to the gear. Since the flange is connected to the camshaft for the fuel injection pump, the fuel injection timing is also changed. No adjustment can be made in the timing advance unit.

Air Inlet And Exhaust System

The air inlet and exhaust system components are: air cleaner, turbocharger, inlet manifold (passages inside the cylinder block), cylinder head, valves and valve system components, and exhaust manifold.



Air Inlet And Exhaust System

(1) Exhaust manifold.
(2) Pipe to inlet manifold.
(3) Engine cylinders.
(4) Air inlet.
(5) Compressor wheel.
(6) Turbine wheel.
(7) Exhaust outlet.



Air Flow Schematic

(1) Exhaust manifold.
(2) Pipe to inlet manifold.
(4) Air inlet.
(7) Exhaust outlet.
(8) Turbocharger.

Clean inlet air from the air cleaner is pulled through air inlet (4) of the turbocharger by the turning of turbocharger compressor wheel (5). The compressor wheel causes a compression of the air. The air then goes through pipe to inlet manifold (2) of the engine. When the inlet valves open, the air goes into engine cylinders (3) and is mixed with the fuel for combustion. When the exhaust valves open, the exhaust gases go out of the engine cylinders and into exhaust manifold (1). From exhaust manifold, the exhaust gases go through the blades of turbine wheel (6). This causes the turbine wheel and compressor wheel to turn. The exhaust gases then go out exhaust outlet (7) of the turbocharger.

Aftercooler

The aftercooler cools the air coming out of the turbocharger before it goes into the inlet manifold. The aftercooler is located toward the rear of the engine between the cylinder heads. Coolant from the water pump flows through a pipe into the aftercooler. It flows through the core assembly, then out of the aftercooler through a different pipe into the rear of the cylinder block. Inlet air from the compressor side of the turbocharger flows into the aftercooler through pipes. The air passes through the core assembly. This lowers the temperature of the air to approximately 93°C (200°F). The cooler air goes out the bottom of the aftercooler into the inlet manifold. The purpose of this is to make the air going into the combustion chambers more dense. The more dense the air is, the more fuel the engine can burn efficiently. This gives the engine more power.

Turbocharger

The turbocharger is installed at the top, rear of the engine on a cross pipe for the two exhaust manifolds. All the exhaust gases from the engine go through the turbocharger.



Typical Example

(1) Turbocharger.
(2) Cross pipes.
(3) To exhaust manifold.



Turbocharger

(4) Air inlet.
(5) Compressor wheel.
(6) Turbine wheel.
(7) Exhaust outlet.
(8) Compressor housing.
(9) Oil inlet port.
(10) Thrust collar.
(11) Thrust bearing.
(12) Turbine housing.
(13) Spacer.
(14) Air outlet.
(15) Oil outlet port.
(16) Bearing.
(17) Coolant passages.
(18) Bearing.
(19) Exhaust inlet.

The exhaust gases go through the blades of turbine wheel (6). This causes the turbine wheel and compressor wheel (5) to turn, which causes a compression of the inlet air.

When the load on the engine is increased, more fuel is put into the engine. This makes more exhaust gases and will cause the turbine and compressor wheels of the turbocharger to turn faster. As the turbocharger turns faster, it gives more inlet air and makes it possible for the engine to burn more fuel and will give the engine more power.

Maximum rpm of the turbocharger is controlled by the rack setting, the high idle speed setting and the height above sea lever at which the engine is operated.


NOTICE

If the high idle rpm or the rack setting is higher than given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche (for the height above sea level at which the engine is operated), there can be damage to engine or turbocharger parts. Damage will result when increased heat and/or friction, due to the higher engine output, goes beyond the engine cooling and lubrication system abilities.


Bearings (16 and 18) for the turbocharger use engine oil under pressure for lubrication. The oil comes in through the oil inlet port (9) and goes through passages in the center section for lubrication of the bearings. Oil from the turbocharger goes out through the oil outlet port (15) in the bottom of the center section and goes back to the engine lubrication system.

This type turbocharger has coolant passages (17) around the bearings to cool the oil in these areas. Engine coolant is taken from the top, rear of the engine and sent into the rear of the turbocharger (center section). The coolant flows through the passages around the bearings, and out the front of the turbocharger (center section) back to the radiator top tank.

The fuel rack adjustment is done at the factory for a specific engine application. The governor housing and turbocharger are sealed to prevent changes in the adjustment of the rack and the high idle speed setting.

Valve System Components

The valve system components control the flow of inlet air and exhaust gases into and out of the cylinders during engine operation.

The crankshaft gear drives the camshaft gear. The camshaft gear must be timed to the crankshaft gear to get the correct relation between piston and valve movement.

The camshaft has two cams for each cylinder. One cam controls the exhaust valves, the other controls the inlet valves.



Valve System Components

(1) Inlet bridge.
(2) Inlet rocker arm.
(3) Push rod.
(4) Rotocoil.
(5) Valve spring.
(6) Valve guide.
(7) Inlet valves.
(8) Lifter.
(9) Camshaft.



Valve System Components (Typical Illustration)

(1) Inlet bridge.
(2) Inlet rocker arm.
(7) Inlet valves.
(10) Exhaust rocker arm.
(11) Exhaust bridge.
(12) Exhaust valves.

As the camshaft turns, the lobes of camshaft (9) cause lifters (8) to go up and down. This movement makes push rods (3) move rocker arms (2 and 10). Movement of the rocker arms makes the bridges move up and down on dowels mounted in the cylinder head. The bridges let one rocker arm open and close two valves (inlet or exhaust). There are two inlet and two exhaust valves for each cylinder.

Rotocoils (4) cause the valves to turn while the engine is running. The rotation of the valves keeps the deposit of carbon on the valves to a minimum and gives the valves longer service life.

Valve springs (5) cause the valves to close when the lifters move down.

Lubrication System

Oil Flow Through The Engine Oil Cooler And Engine Oil Filters



Schematic Of Oil Flow

(1) To oil manifold.
(2) Filter bypass valve.
(3) Engine oil cooler.
(4) Cooler bypass valve.
(5) Engine oil pump.
(6) Oil pan.
(7) Engine oil filters.

With the engine warm (normal operation), oil is pulled from oil pan (6) through a suction bell assembly and pipe to engine oil pump (5). The engine oil pump sends oil to a passage in the cylinder block. The oil then goes through engine oil cooler bypass valve (4) into engine oil cooler (3). The oil goes out of the engine oil cooler through engine oil filters (7). The clean oil then goes through oil filter bypass valve (2), then into the oil manifold on the right side of the cylinder block.

When the engine is cold (starting condition), bypass valves (2 and 4) open because cold oil with high viscosity causes a restriction to the oil flow through engine oil cooler (3) and engine oil filters (7). With the bypass valves open, oil flows directly through passages in the valve body to the oil manifold.

When oil gets warm, the pressure difference at the bypass valves decreases and the bypass valves close. This gives normal oil flow through engine oil cooler (3) and engine oil filters (7).

The bypass valves will also open when there is a restriction in the engine oil cooler or engine oil filters. This action does not let an engine oil cooler or engine oil filter with a restriction prevent the lubrication of the engine.

There is also a bypass valve in engine oil pump (5). This bypass valve controls the pressure of the oil from the engine oil pump. The engine oil pump can put more oil into the system than is needed. When there is more oil than needed, the oil pressure goes up and the bypass valve will open. This lets the oil that is not needed to go back to the inlet oil passage of the engine oil pump.

Oil Flow In The Engine



Schematic Of Oil Flow In The 3408C Engine

(1) Passage is plugged.
(2) Passage (to rear idler gear).
(3) Passage (to rocker arm shaft).
(4) To turbocharger.
(5) Passage (to fuel injection pump housing, and governor).
(6) Rocker arm shaft.
(7) Passages (to rocker arm shaft and valve lifters).
(8) Passages (to valve lifters).
(9) Camshaft bearing bores.
(10) Piston cooling jets.
(11) To SCAC water pump.
(12) Oil manifold (left side).
(13) To timing gear housing.
(14) Passage (to front idler gear).
(15) Oil supply line (to manifold in cylinder block).
(16) Oil manifold (right side).
(17) Main bearing bores.

The oil manifolds are cast into the sides of the cylinder block. Oil goes into oil manifold (16) from the bypass valve body. From oil manifold (16) oil is sent to oil manifold (12) through drilled passages in the cylinder block that connect main bearing bores (17) and camshaft bearing bores (9). Oil goes through holes in the bearings and gives them lubrication. Oil from the main bearings goes through holes drilled in the crankshaft to give lubrication to the connecting rod bearings. A small amount of oil from the oil manifolds goes through piston cooling jets (10) to make the pistons cooler.

Oil goes through grooves in the outside of the front and rear camshaft bearings to passages (7 and 8). The oil in these passages gives lubrication to the valve lifters and rocker arm shafts. Holes in the rocker arm shafts lets the oil give lubrication to the valve system components in the cylinder head.

The fuel injection pump and governor gets oil from passage (5) in the cylinder block. There is a small gear pump between the injection pump housing and the governor. This pump sends oil under pressure for the hydraulic operation of the hydra-mechanical governor. The automatic timing advance unit gets oil from the injection pump housing, through the camshaft for the fuel injection pumps.

The idler gear bore gets oil from passage (14) in the cylinder block, oil then goes through the shaft for the bearings of the idler gear installed on the front of the cylinder block.

The bearing for the balancer gear at the rear of the engine (3408C only) gets oil through a passage in the balancer gear shaft that is connected to passage (2).



Turbocharger Lubrication (Typical Example)

(18) Oil supply line (to turbocharger).
(19) Oil drain line (from turbocharger).

Oil supply line (18) gives oil to the turbocharger impeller shaft bearings. The oil goes out of the turbocharger through oil drain line (19) to the flywheel housing.

Oil that gives pressure lubrication to gear shafts and bearings then flows free to give lubrication to the gear teeth. After the oil for lubrication has done its work it flows back to the oil pan.



Schematic Of Oil Flow In The 3412C Engine

(1) Passage is plugged.
(3) Passage (to rocker arm shaft).
(4) To turbocharger.
(5) Passage (to fuel injection pump housing, and governor).
(6) Rocker arm shaft.
(7) Passages (to rocker arm shaft and valve lifters).
(8) Passages (to valve lifters).
(9) Camshaft bearing bores.
(10) Piston cooling jets.
(11) To SCAC water pump.
(12) Oil manifold (left side).
(13) To timing gear housing.
(14) Passage (to front idler gear).
(15) Oil supply line (to manifold in cylinder block).
(16) Oil manifold (right side).
(17) Main bearing bores.

Cooling System

Jacket Water Aftercooler



Cooling System Schematic

(1) Aftercooler elbow.
(2) Aftercooler.
(3) Front housing.
(4) Temperature regulator housing.
(5) Bypass lines.
(6) Water cooled exhaust manifold.
(7) Jacket water coolant source.
(8) Water cooled turbocharger.
(9) Engine oil cooler.
(10) Jacket water pump.

This engine has a pressure type cooling system. A pressure type cooling system gives two advantages. The first advantage is that the cooling system can have safe operation at a temperature that is higher than the normal boiling (steam) point of water. The second advantage is that this type system prevents cavitation (the sudden making of low pressure bubbles in liquids by mechanical forces) in the water pump. With this type system, it is more difficult for an air or steam pocket to be made in the cooling system.

In normal operation (engine warm), jacket water pump (10) receives coolant through the inlet connection. The jacket water pump (10) forces water out in two directions. Part of it flows to the aftercooler (2). The coolant goes through the aftercooler core and enters into the cylinder block at the top rear through aftercooler elbow (1). Part of the coolant flows through the engine oil cooler (9) and into the side of the cylinder block.

Coolant moves through the cylinder block to the cylinder heads. The coolant then goes to the temperature regulator housing (4). The temperature regulators are open and most of the coolant goes through the outlets and back to the coolant source.

NOTE: The water temperature regulator is an important part of the cooling system. It divides coolant flow between jacket water coolant source (7) and bypass lines (5) as necessary to maintain the correct temperature. If the water temperature regulator is not installed in the system, there is no mechanical control, and most of the coolant will take the path of least resistance through the bypass. This will cause the engine to overheat in hot weather. In cold weather, even the small amount of coolant that goes back to the coolant source is too much, and the engine will not get to normal operating temperatures.

When the engine is cold, the water temperature regulator is closed, and the coolant is stopped from going back to the coolant source. The coolant goes from the temperature regulator housing (4) back to the jacket water pump (10) through bypass lines (5).

These engines are equipped with a water cooled exhaust manifold (6) and a water cooled turbocharger (8). The coolant for the water cooled exhaust manifold comes from the back of the cylinder head through the water cooled exhaust manifold and out into the water temperature regulator housing. The coolant for the water cooled turbocharger comes from the engine oil cooler (9) through the tube to the water cooled turbocharger. The coolant goes out of the water cooled turbocharger and into the water cooled exhaust manifold.

Separate Circuit Aftercooler



Cooling System Schematic

(1) Separate circuit coolant source.
(2) Aftercooler.
(3) Water cooled exhaust manifold.
(4) Front housing.
(5) Temperature regulator housing.
(6) Bypass lines.
(7) Separate circuit water pump.
(8) Water cooled turbocharger.
(9) Engine oil cooler.
(10) Water pump.
(11) Jacket water coolant source.

Jacket Water System

This engine has a pressure type cooling system. A pressure type cooling system gives two advantages. The first advantage is that the cooling system can have safe operation at a temperature that is higher than the normal boiling (steam) point of water. The second advantage is that this type system prevents cavitation (the sudden making of low pressure bubbles in liquids by mechanical forces) in the water pump. With this type system, it is more difficult for an air or steam pocket to be made in the cooling system.

In normal operation (engine warm), water pump (10) receives coolant through the inlet connection and sends the coolant to engine oil cooler (9) and the oil cooler bypass. The engine oil cooler outlet sends the coolant from the cooler and bypass to the engine cylinder block. The coolant to the cylinder block circulates through the block up through the cylinder heads, on to the water temperature regulator housing (5). Part of the coolant in water temperature regulator housing (5) flows into water pump (10), and part of the coolant passes through open water temperature regulators through the outlet connections to be cooled. The water pump (10) will pump the cooled coolant through the engine to keep the cycle going.

These engines are equipped with a water cooled exhaust manifold (3) and a water cooled turbocharger (8). The coolant for the exhaust manifold comes from the back of the cylinder head through the exhaust manifold and out into the water temperature regulator housing (5). The coolant for water cooled turbocharger (8) comes from the engine oil cooler through the tube to the water cooled turbocharger. The coolant goes out of the water cooled turbocharger and into water cooled exhaust manifold (3).

NOTE: The water temperature regulator is an important part of the cooling system. It divides coolant flow between the coolant source and bypass lines (6) as necessary to maintain the correct temperature. If the water temperature regulator is not installed in the system, there is no mechanical control, and most of the coolant will take the path of least resistance through the bypass. This will cause the engine to overheat in hot weather. In cold weather, even the small amount of coolant that goes through the radiator or heat exchanger is too much, and the engine will not get to normal operation temperatures.

When the engine is cold, the water temperature regulators are closed. The coolant in the temperature regulator housing (5) flows through bypass lines (6) to water pump (10). The coolant continues to flow through system as described above except the coolant does not flow out to be cooled.

Separate Circuit Aftercooler (SCAC) System

The aftercooler (2) is cooled by a separate circuit. The separate circuit is used to maintain a specific and constant water temperature. Water is pumped from separate circuit coolant source (1) by separate circuit water pump (7) through the aftercooler and back to the water supply.

Basic Block

Cylinder Block, Liners And Heads

The cylinders in the left side of the block make an angle of 65 degrees with the cylinders in the right side of the block. The main bearing caps are fastened to the block with two bolts per cap.

The cylinder liners can be removed for replacement. The top surface of the block is the seat for the cylinder liner flange. Engine coolant flows around the liners to keep them cool. Three O-ring seals around the bottom of the liner make a seal between the liner and the block.

The engine has a single, cast head on each side. Four vertical valves (two inlet and two exhaust), controlled by a pushrod valve system, are used per each cylinder. The opening for the fuel nozzles is located between the four valves. Series ports (passages) are used for both inlet and exhaust valves.

A steel spacer plate is used between the cylinder head and block. A thin gasket is used between the (plate and liners) and the block to seal water and oil. A thick gasket of metal and asbestos is used between the plate and the head to seal combustion gases, water and oil.

The size of the pushrod openings through the head permits the removal of the valve lifters with the head installed.

Valve guides without shoulders are pressed into the cylinder head.

Pistons, Rings And Connecting Rods

The aluminum pistons have three rings; two compression rings and one oil ring. All rings are located above the piston pin bore. The two compression rings are of the Keystone type, which have a tapered shape. The seat for the rings is an iron band that is cast into the piston. The action of the rings in the piston groove, which is also tapered, helps prevent seizure of the rings caused by too much carbon deposits. The oil ring is a standard (conventional) type. Oil returns to the crankcase through openings in the oil ring groove.

The piston pin is held in place by two snap rings that fit in grooves in the pin bore of the piston. The connecting rod has a taper on the pin bore end. This gives the rod and piston more strength in the areas with the most load.

Oil spray tubes, located on the cylinder block main webs, direct oil to cool and give lubrication to the piston components and cylinder walls.

Crankshaft

The crankshaft changes the combustion forces in the cylinder into usable rotating torque which powers the machine. Vibration, caused by combustion impacts along the crankshaft, is kept small by a vibration damper on the front of the crankshaft.

There is a gear at the front of the crankshaft to drive the timing gears and the engine oil pump. Seals and wear sleeves are used at both ends of the crankshaft for easy replacement and a reduction of maintenance cost. Pressure oil is supplied to all bearing surfaces through drilled holes in the crankshaft. The crankshaft is supported by five main bearings on the 3408C and seven main bearings on the 3412C. A thrust plate at either side of the center main bearing controls the end play of the crankshaft.

The engine has a single camshaft that is driven at the front end. It is supported by five bearings on the 3408C and seven bearings on the 3412C. As the camshaft turns, each cam (lobe) (through the action of the valve system components) moves either two exhaust valves or two inlet valves for each cylinder. The camshaft gear must be timed to the crankshaft gear. The relation of the cam (lobes) to the camshaft gear cause the valves in each cylinder to open and close at the correct time.

Vibration Damper



Cross Section Of A Vibration Damper

(1) Flywheel ring.
(2) Rubber ring.
(3) Inner hub.

The twisting of the crankshaft, due to the regular power impacts along its length, is called twisting (torsional) vibration. The vibration damper is installed on the front end of the crankshaft. It is used for reduction of torsional vibrations and stops the vibration from building up to amounts that cause damage.

The damper is made of a flywheel ring (1) connected to an inner hub (3) by a rubber ring (2). The rubber makes a flexible coupling between the flywheel ring and the inner hub.

Electrical System

The electrical system can have three separate circuits: the charging circuit, the starting circuit and the low amperage circuit. Some of the electrical system components are used in more than one circuit. The battery (batteries), circuit breaker, ammeter, cables and wires from the battery are all common in each of the circuits.

The charging circuit is in operation when the engine is running. An alternator makes electricity for the charging circuit. A voltage regulator in the circuit controls the electrical output to keep the battery at full charge.

The starting circuit is in operation only when the start switch is activated.

The electrical systems include a Diagnostic Connector which is used when testing the charging and starting circuits.

The low amperage circuit and the charging circuit are both connected to the same side of the ammeter. The starting circuit connects to the opposite side of the ammeter.


NOTICE

Never operate the alternator without the battery in the circuit. Making or breaking an alternator connection with heavy load on the circuit can cause damage to the regulator.


Charging System Components

Alternator (4N3986, 4N3987)



Alternator

(1) Rectifier.
(2) Rotor assembly.
(3) Stator winding.
(4) Coil and support assembly.
(5) Ball bearing.
(6) Regulator.
(7) Roller bearing.
(8) Fan.

The alternator is driven by belts from the crankshaft pulley. This alternator is a three phase, self-rectifying charging unit, and the regulator is part of the alternator. The alternators have a 60 amp output.

This alternator design has no need for slip rings or brushes, and the only part that has movement is the rotor assembly. All conductors that carry current are stationary. The conductors are the field winding, stator windings, six rectifying diodes and the regulator circuit components.

The rotor assembly has many magnetic poles like fingers with air space between each opposite pole. The poles have residual magnetism (like permanent magnets) that produce a small amount of magnetic lines of force (magnetic field) between the poles. As the rotor assembly begins to turn between the field winding and the stator windings, a small amount of alternating current (AC) is produced in the stator windings from the small magnetic lines of force made by the residual magnetism of the poles. This AC current is changed to direct current (DC) when it passes through the diodes of the rectifier bridge. Most of this current goes to charge the battery and to supply the low amperage circuit, and the remainder is sent on to the field windings. The DC current flow through the field windings (wires around an iron core) now increases the strength of the magnetic lines of force. These stronger liners of force now increase the amount of AC current produced in the stator windings. The increased speed of the rotor assembly also increases the current and voltage output of the alternator.

Alternator (6T1395)



Alternator

(1) Rotor assembly.
(2) Stator assembly.
(3) Brush assembly.
(4) Regulator.
(5) Bearings.
(6) Capacitor.
(7) Slip rings.

The alternator is driven by belts from the crankshaft pulley. It is a 24 volt, 35 ampere unit with a regulator which is a solid state (transistor, stationary parts) electronic switch installed on the side opposite the pulley. The alternator is made up of a head assembly on the drive end, rotor assembly, stator assembly, rectifier and heat removal assemblies, brush and holder assembly, head assembly on the ring and regulator.

The rotor assembly has the field windings (wires around an iron core) which make magnetic lines of force when direct current (DC) flows through them. As the rotor turns, the magnetic lines of force are broken by the stator. This makes an alternating current (AC) in the stator. The rectifier has diodes which change the alternating current (AC) from the stator to direct current (DC). Most of the direct current (DC) goes to charge the battery and make a supply of direct current (DC) for the low amperage circuit. The remainder of the direct current (DC) is sent to the field windings through the brushes.

Alternator Regulator (7T5665, 3T6354, 6T9445)

The voltage regulator is a solid state (transistor, stationary parts) electronic switch. It feels the voltage in the system and switches on and off many times a second to control the field current (DC current to the field windings) for the alternator to make the needed voltage output.

Starting System Components

Solenoid

A solenoid is an electromagnetic switch that does two basic operations:

a. Closes the high current starting motor circuit with a low current start switch circuit.

b. Engages the starting motor pinion with the ring gear.



Typical Solenoid Schematic

The solenoid has windings (one or two sets) around a hollow cylinder. There is a plunger (core) with a spring load inside the cylinder that can move forward and backward. When the start switch is closed and electricity is sent through the windings, a magnetic field is made that pulls the plunger forward in the cylinder. This moves the shift lever (connected to the rear of the plunger) to engage the pinion drive gear with the ring gear. The front end of the plunger then makes contact across the battery and motor terminals of the solenoid, and the starting motor begins to turn the flywheel of the engine.

When the start switch is opened, current no longer flows through the windings. The spring now pushes the plunger back to the original position, and, at the same time, moves the pinion gear away from the flywheel.

When two sets of windings in the solenoid are used, they are called the hold-in winding and the pull-in winding. Both have the same number of turns around the cylinder, but the pull-in winding uses a larger diameter wire to produce a greater magnetic field. When the start switch is closed, part of the current flows from the battery through the hold-in windings, and the rest flows through the pull-in windings to motor terminal, then through the motor to ground.

When the solenoid is fully activated (connection across battery and motor terminal is complete), current is shut off through the pull-in windings. Now only the smaller hold-in windings are in operation for the extended period of time it takes to start the engine. The solenoid will now take less current from the battery, and heat made by the solenoid will be kept at an acceptable level.

Starting Motor

The starter motor is used to turn the engine flywheel fast enough to get the engine running.



Starting Motor

(1) Field.
(2) Solenoid.
(3) Clutch.
(4) Pinion.
(5) Commutator.
(6) Brush assembly.
(7) Armature.

The starting motor has a solenoid. When the start switch is turned to the START position, the solenoid will be activated electrically. The solenoid core will now move to push the starting pinion, by a mechanical linkage, to engage with the ring gear on the flywheel of the engine. The starting pinion will engage with the ring gear before the electric contacts in the solenoid close the circuit between the battery and the starting motor. When the circuit between the battery and the starting motor is complete, the pinion will turn the engine flywheel. A clutch gives protection for the starting motor so that the engine, when it starts to run, can not turn the starting motor too fast. When the start switch is released, the starting pinion will move away from the flywheel ring gear.

Magnetic Switch

A magnetic switch (relay) is used sometimes for the starter solenoid circuit. Its operation electrically is the same as the solenoid. Its function is to reduce the current load on the start switch and control current to the starter solenoid.

Other Components

Circuit Breaker

The circuit breaker is a switch that opens the battery circuit if the current in the electrical system goes higher than the rating of the circuit breaker.

A heat activated metal disc with a contact point makes complete the electric current through the circuit breaker. If the current in the electrical system gets too high, it causes the metal disc to get hot. This heat causes a distortion of the metal disc which opens the contacts and breaks the circuit.

Shutoff Solenoid

The rack shutoff solenoid, when activated, moves the shutoff lever in the governor housing which in turn moves the fuel rack to the fuel closed position. The solenoid is activated by a manual control switch.

Air Starting System

The air starting motor is used to turn the engine flywheel fast enough to get the engine running.



Typical Air Starting System

(1) Air start control valve.
(2) Air starting motor.
(3) Relay valve.
(4) Oiler.

The air starting motor (2) can be mounted on either side of the engine. Air is normally contained in a storage tank and the volume of the tank will determine the length of time the engine flywheel can be turned. The storage tank must hold this volume of air at 1720 kPa (250 psi) when filled.

For engines which do not have heavy loads when starting, the regulator setting is approximately 690 kPa (100 psi). This setting gives a good relationship between cranking speeds fast enough for easy starting and the length of time the air starting motor can turn the engine flywheel before the air supply is gone.

If the engine has a heavy load which can not be disconnected during starting, the setting of the air pressure regulating valve needs to be higher in order to get high enough speed for easy starting.

The air consumption is directly related to speed; the air pressure is related to the effort necessary to turn the engine flywheel. The setting of the air pressure regulator can be up to 1030 kPa (150 psi) if necessary to get the correct cranking speed for a heavily loaded engine. With the correct setting, the air starting motor can turn the heavily loaded engine as fast and as long as it can turn a lightly loaded engine.

Other air supplies can be used if they have the correct pressure and volume. For good life of the air starting motor, the supply should be free of dirt and water. A lubricator with 10W non detergent oil [for temperatures above 0°C (32°F)], or air tool oil [for temperatures above 0°C (32°F)] should be used with the starting system. The maximum pressure for use in the air starting motor is 1030 kPa (150 psi).



Air Starting Motor

(5) Air inlet.
(6) Vanes.
(7) Rotor.
(8) Pinion.
(9) Gears.
(10) Piston.
(11) Piston spring.

The air from the supply goes to relay valve (3). The air start control valve (1) is connected to the line before the relay valve. The flow of air is stopped by the relay valve until air start control valve (1) is activated. The air from air start control valve goes to piston (10) behind pinion (8) for the starter. The air pressure on piston (10) puts piston spring (11) in compression and puts pinion (8) in engagement with the flywheel gear. When the pinion is in engagement, air can go out through another line to relay valve. The air activates relay valve which opens the supply line to the air starting motor.

The flow of air goes through the oiler (lubricator) (4) where it picks up lubrication for the air starting motor.

The air with lubrication goes into the air motor through air inlet (5). The pressure of the air pushes against vanes (6) in rotor (7), and then exhausts through the outlet. This turns the rotor which is connected by gears (9) and a drive shaft to starter pinion (8) which turns the engine flywheel.

When the engine starts running, the flywheel will start to turn faster than pinion (8). The pinion (8) retracts under this condition. This prevents damage to the motor, pinion (8) or flywheel gear.

When air start control valve (1) is released, the air pressure and flow to piston (10) behind pinion (8) is stopped, piston spring (11) retracts pinion (8). Relay valve (3) stops the flow of air to the air starting motor.

Testing & Adjusting

Troubleshooting

Troubleshooting can be difficult. The Troubleshooting Index gives a list of possible problems. To make a repair to a problem, make reference to the cause and correction on the pages that follow.

This list of problems, causes, and corrections will only give an indication of where a possible problem can be, and what repairs are needed. Normally, more or other repair work is needed beyond the recommendations in the list.

Remember that a problem is not normally caused only by one part, but by the relation of one part with other parts. This list is only a guide and can not give all possible problems and corrections. The service personnel must find the problem and its source, then make the necessary repairs.

Troubleshooting Problem List

1. Engine Will Not Turn When Start Switch Is On.

2. Engine Will Not Start.

3. Engine Misfires Or Runs Rough.

4. Stall At Low RPM.

5. Sudden Changes In Engine RPM.

6. Not Enough Power.

7. Too Much Vibration.

8. Loud Combustion Noise.

9. Valve Train Noise (Clicking)

10. Oil In Cooling System.

11. Mechanical Noise (Knock) In Engine.

12. Fuel Consumption Too High.

13. Loud Valve Train Noise.

14. Too Much Valve Lash.

15. Valve Rotocoil Or Spring Lock Is Free.

16. Oil At The Exhaust.

17. Little Or No Valve Lash.

18. Engine Has Early Wear.

19. Coolant In Lubrication Oil.

20. Too Much Black Or Gray Smoke.

21. Too Much White Or Blue Smoke.

22. Engine Has Low Oil Pressure.

23. Engine Uses Too Much Lubrication Oil.

24. Engine Coolant Is Too Hot.

25. Exhaust Temperature Is Too High.

26. Starting Motor Does Not Turn.

27. Alternator Gives No Charge.

28. Alternator Charge Rate Is Low Or Not Regular.

29. Alternator Charge Rate Is Too High.

30. Alternator Has Noise.

Troubleshooting Problems

Problem 1: Engine Crankshaft Will Not Turn When Start Switch Is On

Probable Cause:

1. Battery Has Low Output

Make reference to Problem 26.

2. Wires Or Switches Have Defect

Make reference to Problem 26.

3. Starting Motor Solenoid Has A Defect

Make reference to Problem 26.

4. Starting Motor Has A Defect

Make reference to Problem 26.

5. Internal Problem Prevents Engine Crankshaft From Turning

If the crankshaft can not be turned after the driven equipment is disconnected, remove the fuel nozzles and check for fluid in the cylinders while the crankshaft is turned. If fluid in the cylinders is not the problem, the engine must be disassembled to check for other internal problems. Some of these internal problems are bearing seizure, piston seizure, wrong pistons installed in the engine, and valves making contact with pistons.

Problem 2: Engine Will Not Start

Probable Cause:

1. Starting Motor Turns Too Slow

Make reference to Problem 26 and Problem 27.

2. Dirty Fuel Filter

Install new fuel filter.

3. Dirty Or Broken Fuel Lines

Clean or install new fuel lines as necessary.

4. Fuel Transfer Pump

At starting rpm, the minimum fuel pressure from fuel transfer pump must be 35 kPa (5 psi). If fuel pressure is less than 35 kPa (5 psi), change the fuel filter element. Look for air in the fuel system. If fuel pressure is still low, install a new fuel transfer pump.

5. No Fuel To Cylinders

Put fuel in fuel tank. "Prime" (remove the air and/or low quality fuel) the fuel system.

6. Poor Quality Fuel

Remove the fuel from the fuel tank. Install a new fuel filter element. Put a good grade of clean fuel in the fuel tank. Refer to Diesel Fuels and Your Engine, SEBD0717.

7. Wrong Fuel Injection Timing

Make adjustment to timing.

Problem 3: Engine Misfires Or Runs Rough

Probable Cause:

1. Fuel Pressure Is Low

Make sure there is fuel in the fuel tank. Look for leaks or bad bends in the fuel line between fuel tank and fuel transfer pump. Look for air in the fuel system, sticking, binding or defective fuel bypass valve. Check fuel pressure. The outlet pressure of the fuel transfer pump is 230 ± 35 kPa (33 ± 5 psi) at full load speed.

If fuel pressure is lower than 140 kPa (20 psi), install a new filter element. If fuel pressure is still low, install a new fuel transfer pump.

2. Air In Fuel System

Find the air leak in the fuel system and correct it. If air is in the fuel system, it will probably get in on the suction side of fuel transfer pump.

3. Leak Or Break In Fuel Line Between Fuel Injection Pump And Fuel Injection Nozzle

Install a new fuel line.

4. Wrong Valve Lash

Make adjustment according to the subject, Valve Lash Setting.

5. Defect In Fuel Injection Nozzle(s) Or Fuel Injection Pump(s)

Run at rpm that causes engine to misfire the most or run the roughest. Then loosen a fuel injection line nut at the valve cover base for each cylinder, one at a time. Find the cylinder where a loosened fuel line nut does not change the way the engine runs. Test the injection pump and injection nozzle for that cylinder. Install new parts where needed.

6. Wrong Fuel Injection Timing

Make adjustment to timing.

7. Bent Or Broken Push Rod

Replacement of push rod is necessary.

8. Fuel Has "Cloud Point" Higher Than Atmospheric Temperature ("Cloud Point" = Temperature Which Makes Wax Form In Fuel.)

Drain the fuel tank, lines, and fuel injection pump housing. Change the fuel filter. Fill the tank with fuel which has the correct "cloud point" and remove the air from the system with the priming pump.

Problem 4: Stall At Low RPM

Probable Cause:

1. Fuel Pressure Is Low

Make sure there is fuel in the fuel tank. Look for leaks or bad bends in the fuel line between fuel tank and fuel transfer pump. Look for air in the fuel system, sticking, binding or defective fuel bypass valve. Check fuel pressure. The outlet pressure of the fuel transfer pump is 230 ± 35 kPa (33 ± 5 psi) at full load speed.

If fuel pressure is lower than 140 kPa (20 psi), install a new filter element. If fuel pressure is still low, install a new fuel transfer pump.

2. Idle RPM Too Low

Make adjustment to governor so idle rpm is the same as given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche.

3. Defect In Fuel Injection Nozzle(s)

Install a new fuel injection nozzle(s).

4. Engine Accessories

Check engine accessories for damage and correct adjustment. If necessary, disconnect the accessories and test the engine.

5. Defect In Fuel Injection Pump(s)

Install new parts if needed.

Problem 5: Sudden Changes In Engine Speed (RPM)

Probable Cause:

1. Failure Of Governor Or Fuel Injection Pump

Look for damaged or broken springs, linkage or other parts. Remove the governor. Check for free travel of the fuel racks. Be sure fuel injection pumps are installed correctly. Check for correct governor spring. Install new parts for those that have damage or defects.

Problem 6: Not Enough Power

Probable Cause:

1. Poor Quality Fuel

Remove the fuel from the fuel tank. Install a new fuel filter element. Put a good grade of clean fuel in the fuel tank.

2. Fuel Pressure Is Low

Make sure there is fuel in the fuel tank. Look for leaks or bad bends in the fuel line between fuel tank and fuel transfer pump. Look for air in the fuel system, sticking, binding or defective fuel bypass valve. Check fuel pressure. The outlet pressure of the fuel transfer pump is 230 ± 35 kPa (33 ± 5 psi) at full load speed.

If fuel pressure is lower than 140 kPa (20 psi), install a new fuel filter element. If fuel pressure is still low, install a new fuel transfer pump.

3. Leaks In Air Inlet System

Check the pressure in the air inlet manifold. Look for restrictions in the air cleaner.

4. Governor Linkage

Make adjustment to get full travel of linkage. Install new parts for those that have damage or defects.

5. Wrong Valve Lash

Make adjustment according to the subject, Valve Lash Setting.

6. Defect In Fuel Injection Nozzle(s) Or Fuel Injection Pump(s)

Run at rpm that causes engine to misfire the most or run the roughest. Then loosen a fuel line nut on the fuel injection pump for each cylinder, one at a time. Find the cylinder where a loosened fuel line nut does not change the way the engine runs. Test the injection pump and injection nozzle for that cylinder. Install new parts where needed.

7. Wrong Fuel Injection Timing

Make adjustment to timing.

8. Rack Setting Too Low

Make reference to the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche.

9. Turbocharger Has Carbon Deposit Or Other Cause Of Friction

Inspect and repair turbocharger as necessary.

Problem 7: Too Much Vibration

Probable Cause:

1. Loose Bolt Or Nut For Pulley Or Damper

Tighten bolt or nut.

2. Pulley Or Damper Has A Defect

Install a new pulley or damper.

3. Engine Supports Are Loose, Worn, Or Have A Defect

Tighten all bolts that hold engine supports. Install new components if necessary.

4. Engine Misfires Or Runs Rough

Make reference to Problem 3.

5. Fan Blade Not In Balance

Loosen or remove fan belts and operate engine for a short time at the rpm that the vibration was present. If vibration is not still present, make a replacement of the fan assembly.

Problem 8: Loud Combustion Noise (Sound)

Probable Cause:

1. Poor Quality Fuel

Remove the fuel from the fuel tank. Install a new fuel filter element. Put a good grade of clean fuel in the fuel tank. Refer to Diesel Fuels and Your Engine, SEBD0717.

2. Defect In Fuel Injection Nozzle(s)

Install new fuel injection valve(s).

3. Defect In Fuel Injection Pump(s)

Install new fuel injection pump(s)

4. Wrong Fuel Injection Timing

Make adjustment to timing.

Problem 9: Valve Train Noise (Clicking)

Probable Cause:

1. Damage To Valve Spring(s), Locks, Or Broken Or Worn Valve Lifter

Install new parts where necessary. Broken locks can cause the valve to get into the cylinder. This will cause much damage.

2. Not Enough Lubrication

Check lubrication in valve compartment. There must be a strong flow of oil at engine high rpm, but only a small flow of oil at low rpm. Oil passages must be clean, especially those that send oil to the cylinder head.

3. Too Much Valve Lash

Make adjustment according to the subject, Valve Lash Setting.

Problem 10: Oil In Cooling System

Probable Cause:

1. Defect In Core Of Engine Oil Cooler Or Transmission Oil Cooler

Install a new engine oil cooler or transmission oil cooler. Drain and flush cooling system and refill with new coolant.

2. Defect In Spacer Plate Gasket

Install new spacer plate gasket.

3. Failure Of Cylinder Head Gasket

Install a new head gasket.

Problem 11: Mechanical Noise (Knock) In Engine

Probable Cause:

1. Failure Of Bearing For Connecting Rod

Inspect the bearing for the connecting rod and the bearing surface (journal) on the crankshaft. Install new parts where necessary.

2. Damaged Timing Gears

Install new parts where necessary.

3. Damaged Crankshaft

Make replacement of the crankshaft.

4. Defect In Attachment

Repair or install new components.

Problem 12: Fuel Consumption Too High

Probable Cause:

1. Fuel System Leaks

Large changes in fuel consumption may be the result. Inside leaks probably will cause low engine oil pressure and an increase in oil level in the engine. Tighten loose connections or make a replacement of the component that leaks.

2. Fuel And Combustion Noise (Knock)

Make reference to Problems 3 and 6.

3. Wrong Fuel Injection Timing

Make adjustment to timing.

Problem 13: Loud Valve Train Noise

Probable Cause:

1. Damage To Valve Spring(s)

Make replacement of parts with damage.

2. Damage To Camshaft

Make replacement of parts with damage. Clean engine thoroughly. If replacement of camshaft is made, new valve lifters are also necessary.

3. Damage To Valve Lifter

Clean engine thoroughly. Make a replacement of the damaged valve lifters. Inspect camshaft lobes for damage. Look for valves that do not move freely. Make an adjustment to valve lash according to the subject, Valve Lash Setting.

4. Damage To Bridge For Valves Or Bridge Dowel

Make a replacement of the bridge and/or bridge dowel, and adjust as necessary.

Problem 14: Too Much Valve Lash

Probable Cause:

1. Not Enough Lubrication

Check lubrication in valve compartment. There must be a strong flow of oil at engine high rpm, but only a small flow at low rpm. Oil passages must be clean, especially those that send oil to the cylinder head.

2. Rocker Arm Worn At Face That Makes Contact With Bridge

If there is too much wear, install new parts or rocker arms. Make adjustment of valve lash according to the subject, Valve Lash Setting.

3. Bridge Or Bridge Dowel For Valves Worn

Make replacement of the bridge and/or bridge dowel, and adjust as necessary.

4. End Of Valve Stem Worn

If there is too much wear, install new valves. Make adjustment to valve lash according to the subject, Valve Lash Setting.

5. Worn Push Rods

If there is too much wear, install new push rods. Make adjustment to valve lash according to the subject, Valve Lash Setting.

6. Broken Or Worn Valve Lifters

Install new valve lifters. Check camshaft for wear. Check for free movement of valves or bent valve stem. Clean engine thoroughly. Make adjustment of valve lash according to the subject, Valve Lash Setting.

7. Worn Camshaft Lobes

Install a new camshaft. Install new valve lifters if damaged. Check for free movement of valves or bent valve stems. Make adjustment of valve lash according to the subject, Valve Lash Setting.

Problem 15: Valve Rotocoil Or Spring Lock Is Free

Probable Cause:

1. Broken Locks

Broken locks can cause the valve to get into the cylinder. This will cause much damage.

2. Broken Valve Spring(s)

Install new valve spring(s).

3. Broken Valve

Replace valve and other damaged parts.

Problem 16: Oil At The Exhaust

Probable Cause:

1. Too Much Oil In The Valve Compartment

Look at both ends of the rocker arm shaft. Be sure a plug is in each end of the shaft.

2. Worn Valve Guides

Reconditioning of the cylinder head is needed.

3. Worn Piston Rings

Inspect and install new parts as needed.

Problem 17: Little Or No Valve Lash

Probable Cause:

1. Worn Valve Seat Or Face Of Valve

Reconditioning of cylinder head is needed. Make adjustment of valve lash according to the subject, Valve Lash Setting.

Problem 18: Engine Has Early Wear

Probable Cause:

1. Dirt In Lubrication Oil

Remove dirty lubrication oil. Install new engine oil filter elements. Put clean oil in the engine.

2. Air Inlet Leaks

Inspect all gaskets and connections. Make repairs if leaks are found.

3. Fuel Leakage Into Lubrication Oil

This will cause high fuel consumption and low engine oil pressure. Make repairs if leaks are found. Install new parts where needed.

Problem 19:Coolant In Lubrication Oil

Probable Cause:

1. Failure Of Engine Oil Cooler Core

Install a new engine oil cooler. Drain crankcase and refill with clean engine oil. Install new engine oil filter elements.

2. Failure Of Cylinder Head Gasket Or Water Seals

Check cylinder liner projection. Install a new spacer plate gasket and new water seals in the spacer plate. Install a new cylinder head gasket. Tighten the bolts that hold the cylinder head. Refer to Specifications, 3408C & 3412C Marine Engines, SENR1131 for the proper procedure to tighten the cylinder head bolts.

3. Crack Or Defect In Cylinder Head

Install a new cylinder head.

4. Crack Or Defect In Cylinder Block

Install a new cylinder block.

5. Failure Of Liner Seals

Replace seals.

6. Crack Or Defect In Cartridge Of Turbocharger

Install a new turbocharger cartridge.

Problem 20: Too Much Black Or Gray Smoke

Probable Cause:

1. Not Enough Air For Combustion

Check air cleaner for restrictions.

2. Damaged Fuel Injection Nozzle(s)

Install new fuel injection nozzle(s).

3. Wrong Fuel Injection Timing

Make adjustment to timing.

Problem 21: Too Much White Or Blue Smoke

Probable Cause:

1. Too Much Lubrication Oil In Engine

Remove extra oil. Find where extra oil comes from. Put correct amount of oil in engine.

2. Engine Misfires Or Runs Rough

Make reference to Problem 3.

3. Wrong Fuel Injection Timing

Make adjustment to timing.

4. Worn Valve Guides

Reconditioning of cylinder head is necessary.

5. Worn Piston Rings

Install new piston rings. Check condition of cylinder liners.

6. Failure Of Turbocharger Oil Seal

Check inlet manifold for oil. Replace seals and repair turbocharger if necessary.

7. Coolant In Combustion System

Check for cracked head.

Problem 22: Engine Has Low Oil Pressure

Probable Cause:

1. Dirty Engine Oil Filter Or Engine Oil Cooler

Check the operation of bypass valve for the filter. Install new engine oil filter elements if needed. Clean or install new engine oil cooler core. Remove dirty oil from engine. Put clean oil in engine.

2. Diesel Fuel In Lubrication Oil

Find the place where diesel fuel gets into the lubrication oil. Make repairs as needed. Remove the lubrication oil that has diesel in it. Install new engine oil filter elements. Put clean oil in the engine.

3. Too Much Clearance Between Rocker Arm Shaft and Rocker Arms

Check lubrication in valve compartment. Install new parts as necessary.

4. Engine Oil Pump Suction Pipe Has A Defect

Replacement of pipe is necessary.

5. Relief Valve For Engine Oil Pump Does Not Operate Correctly

Clean valve and housing. Install new parts as necessary.

6. Engine Oil Pump Is Worn Or Has A Defect

Repair or make replacement of necessary parts.

7. Too Much Clearance Between Crankshaft And Crankshaft Bearings

Inspect crankshaft and bearings. Install new parts as necessary.

8. Too Much Clearance Between Camshaft And Camshaft Bearings

Install new camshaft bearings. Install new camshaft if necessary.

9. Defect In Oil Pressure Indicator

Install new indicator.

10. Too Much Bearing Clearance For Idler Gear

Inspect bearings and make replacement as necessary.

Problem 23: Engine Uses Too Much Lubrication Oil

Probable Cause:

1. Too Much Lubrication Oil In Engine

Remove extra oil. Find where extra oil comes from. Put correct amount of oil in engine.

2. Oil Leaks

Find all oil leaks. Make repairs as necessary.

3. Oil Temperature Is Too High

Check operation of engine oil cooler. Clean the core of the engine oil cooler. Install new parts if necessary.

4. Too Much Oil In The Valve Compartment

Look at both ends of the rocker arm shaft. Be sure a plug is in each end of the shaft.

5. Worn Valve Guides

Reconditioning of the cylinder head is necessary.

6. Worn Piston Rings And Cylinders

Inspect and install new parts as necessary. Reconditioning of the cylinder block may be necessary.

7. Failure Of Seal Rings In Turbocharger

Check inlet manifold for oil and make repair to turbocharger if necessary.

Problem 24: Engine Coolant Is Too Hot

Probable Cause:

1. Restriction To Flow Of Coolant Through Radiator Core Tubes

Clean and flush radiator.

2. Restriction To Air Flow Through Radiator

Remove all restrictions to air flow.

3. Low Fan Speed

Check for worn or loose fan belts.

4. Not Enough Coolant In System

Add coolant to cooling system.

5. Pressure Relief Valve Has A Defect

Check operation of pressure relief valve. Install a new pressure relief valve if necessary.

6. Combustion Gases In Coolant

Find out where gases get into the cooling system. Make repairs as necessary.

7. Water Temperature Regulators (Thermostats) Or Temperature Indicators Have A Defect

Check water temperature regulators for correct operation. Check temperature indicator operation. Install new parts as necessary.

8. Water Pump Has A Defect

Make repairs or replacement of the water pump as necessary.

9. Too Much Load On The System

Make a reduction to the load.

10. Wrong Fuel Injection Timing

Make adjustment to timing.

11. Torque Converter Or Transmission Does Not Operate Correctly. This Can Cause An Increase In The Coolant Temperature

Make corrections for torque converter or transmission running too hot.

Problem 25: Exhaust Temperature Is Too High

Probable Cause:

1. Air Inlet Or Exhaust System Has A Restriction

Remove restriction.

2. Wrong Fuel Injection Timing

Make an adjustment to the timing.

Problem 26: Starting Motor Does Not Turn

Probable Cause:

1. Battery Has Low Output

Check condition of battery. Charge battery or make replacement as necessary.

2. Wires Or Switch Has Defect

Make repairs or replacement as necessary.

3. Starting Motor Solenoid Has A Defect

Install a new solenoid.

4. Starting Motor Has A Defect

Make repair or replacement of starting motor.

Problem 27: Alternator Gives No Charge

Probable Cause:

1. Loose Drive Belt For Alternator

Make an adjustment to put the correct tension on the drive belt.

2. Charging Or Ground Return Circuit Or Battery Connections Have A Defect

Inspect all cables and connections. Clean and tighten all connections. Make replacement of parts with defect.

3. Rotor (Field Coil) Has A Defect

Install a new rotor.

Problem 28: Alternator Charge Rate Is Low Or Not Regular

Probable Cause:

1. Loose Drive Belt For Alternator

Make an adjustment to put the correct tension on the drive belt.

2. Charging Or Ground Return Circuit Or Battery Connections Have A Defect

Inspect all cables and connections. Clean and tighten all connections. Make replacement of parts with defect.

3. Alternator Regulator Has A Defect

Install a new alternator regulator.

4. Rectifier Diodes Have A Defect

Make replacement of rectifier diode that has a defect.

5. Rotor (Field Coil) Has A Defect

Install a new rotor.

Problem 29: Alternator Charge Rate Is Too High

Probable Cause:

1. Alternator Or Alternator Regulator Has Loose Connections

Tighten all connections to alternator or alternator regulator.

2. Alternator Regulator Has A Defect

Install a new alternator regulator.

Problem 30: Alternator Has Noise

Probable Cause:

1. Drive Belt For Alternator Is Worn Or Has A Defect

Install a new drive belt for the alternator.

2. Loose Alternator Drive Pulley

Check groove in pulley for key that holds pulley in place. If groove is worn, install a new pulley. Tighten pulley nut according to Specifications, 3408C & 3412C Marine Engines, SENR1131.

3. Drive Belt And Drive Pulley For Alternator Are Not In Alignment

Make an adjustment to put drive belt and drive pulley in correct alignment.

4. Worn Alternator Bearings

Install new bearings in the alternator.

5. Rotor Shaft Is Bent

Make a replacement of the rotor shaft.

6. Rectifiers In The Alternator Are Shorted

Make a replacement of the diode assembly.

Fuel System

Either too much fuel or not enough fuel for combustion can be the cause of a problem in the fuel system. Many times work is done on the fuel system when the problem is really with some other part of the engine. The source of the problem is difficult to find, especially when smoke comes from the exhaust. Smoke that comes from the exhaust can be caused by a defective fuel injector, but it can also be caused by one or more of the reasons that follow:

a. Not enough air for good combustion.
b. An overload at high altitude.
c. Oil leakage into combustion chamber.
d. Not enough compression
e. Fuel injection timing incorrect.

Fuel System Inspection

A problem with the components that send fuel to the engine can cause low fuel pressure. This can decrease engine performance.

1. Check the fuel level in the fuel tank. Look at the cap for the fuel tank to make sure the vent is not filled with dirt.

2. Check the fuel lines for fuel leakage. Be sure the fuel supply line does not have a restriction or a bad bend. Verify that the fuel return line has not collapsed in the sections subject to heat.

3. Install a new fuel filter. Clean the primary fuel filter.

4. To remove air from the fuel system, use the procedure that follows:

a. Use the priming pump to remove air from the low pressure side of the fuel system.

b. Loosen one-half turn the fuel injection line nuts at each adapter in the valve cover base. Move throttle lever to Low Idle position. Use the starting motor to turn the engine until fuel without air flows from the loose connections. Tighten the nuts.

NOTE: Because of the check assemblies in the injection pump outlets the priming pump will not give enough pressure to remove air from the fuel injection lines.

5. Inspect the fuel bypass valve to see that there is no restriction to good operation.

Checking Engine Cylinders Separately

An easy check can be made to find the cylinder that runs rough (misfires) and causes black smoke to come out of the exhaust pipe.

Run the engine at the speed that is the roughest. Loosen the fuel line nut at a fuel injection pump. This will stop the flow of fuel to that cylinder. Do this for each cylinder until a loosened fuel line is found that makes no difference in engine performance. Be sure to tighten each fuel line nut after the test, before the next fuel line nut is loosened. Check each cylinder by this method. When a cylinder is found where the loosened fuel line nut does not make a difference in engine performance, test the injection pump and fuel injection nozzle for that cylinder.

Temperature of an exhaust manifold port, when the engine runs at low idle speed, can also be an indication of the condition of a fuel injection nozzle. Low temperature at an exhaust manifold port is an indication of no fuel to the cylinder. This can possibly be an indication of an fuel injection nozzle with a defect. Extra high temperature at an exhaust manifold port can be an indication of too much fuel to the cylinder, also caused by an fuel injection nozzle with a defect.

The most common defects found with the fuel injection nozzles are:

1. Carbon on tip of the nozzle or in the nozzle orifice.

2. Orifice wear.

3. Dirty nozzle screen.

Testing Fuel Injection Nozzles

Testing of the fuel injection nozzles must be done off the engine. Perform the following tests using the 5P4150 Nozzle Testing Group to determine if nozzle performance is acceptable:

Valve Opening Pressure Test

Flush The Nozzle

Tip Leakage Test

Orifice Restriction Test

Bleed Screw Leakage Test

Refer to Special Instruction, SEHS7292, for operation of the 5P4150 Nozzle Testing Group.

Fuel Injection Service

Removal of Fuel Injection Pump



Put Rack At Zero Position

(1) Governor control shaft.
(2) Fuel injection pump housing.
(3) 6V6019 Timing Pin.

1. Remove plug from fuel injection pump housing (2).

2. Install 6V6019 Timing Pin (A) with the flat end down in the hole that the plug was removed from.

3. Turn governor control shaft (1) toward High Idle and push down on timing pin (A) until it engages in the slot (groove) in the rack. The rack is now centered (at zero position). The fuel injection pumps can now be removed.

4. Disconnect the fuel lines from the injection pumps.

5. Use the 8T5287 Wrench to loosen the bushing that holds the fuel injection pump in the housing.

6. Install 8S2244 Extractor (5) on the threads of the injection pump. Pull the pump straight out of the bore.

When injection pumps and spacers are removed from the injection pump housing, keep the parts for each pump together so they can be installed back in their original location. Make reference to subject. Checking The Plunger And Lifter Washer On The Injection Pump.

Be careful when injection pumps are disassembled. Do not damage the surface on the plunger. The plunger and barrel for each pump are made as a set. Do not put the plunger of one pump in the barrel of another pump. If one part is worn, install a complete new pump assembly. Be careful when the plunger is put in the bore of the barrel.

Installation of Fuel Injection Pump


NOTICE

The fuel rack must be in the center position before the correct installation of an injection pump is possible.


The procedure to center the fuel rack is shown in the subject, Removal Of Fuel Injection Pump.

To install a fuel injection pump back into the housing bore, use the procedure that follows:



Fuel Pump Installation (Typical Illustration)

(3) Barrel.
(4) Gear segment.
(5) 8S2244 Extractor.
(6) Bushing.

1. Put 8S2244 Extractor (5) on threads of injection pump.

2. Put groove of barrel (3) in alignment with slot of gear segment (4) (slot is on opposite side of gear segment teeth).

3. Look inside the bore of the injection pump housing to find the dowel. Put groove of the barrel in alignment with the dowel and put the injection pump straight down into the bore.

4. Push down on 8S2244 Pump Extractor (5) (hand force only) and install bushing (6) that holds the injection pump in the pump housing. If the pump is in the correct position, the bushing will turn into the threads of the injection pump housing with the fingers until it is even with the top of the housing (except for the pump that is in the position to fire). When bushing is installed correctly, tighten the bushing to 163 ± 14 N·m (120 ± 10 lb ft).


NOTICE

Damage to the housing will be the result if the bushing is too tight. If the bushing is not tight enough, the pump will have leakage.


5. Remove the 6V6019 Pin from injection pump housing and install the plug back in the hole.

6. Move the governor control back to shutoff position. Check to be sure governor control moves freely between fuel-on and shutoff position.

Check for the correct installation of injection pump with the engine stopped. Rack travel from the center position in the fuel-on direction can be checked with governor installed, but the governor and governor piston must be removed to check for full rack travel. Use 6V9128 Rack Position Tool Group and the chart that follows to check rack travel. Make reference to Fuel Rack Setting for installation of 6V9128 Rack Position Tool Group.

With the governor piston and valve removed, the total amount of fuel rack travel (from shutoff position to full load position) is approximately 20.32 mm (.800 in). If the pump is installed wrong (center tooth of gear segment is not in correct notch of fuel rack) fuel rack travel will be less than 20.32 mm (.800 in). The injection pump will have to be removed and then installed correctly.

------ WARNING! ------

If one or more of the fuel injection pumps have been installed wrong, it is possible for the engine to run out of control when started. When any of the fuel injection pumps have been removed and installed with the fuel injection pump housing on the engine, take the precautions (steps) that follow to stop the engine if it starts to overspeed (run out of control).

--------WARNING!------



Turbocharger With Open Air Inlet

(7) Air inlet.

a. Remove the air cleaner so that turbocharger air inlet (7) is open as shown.


Stopping The Engine

b. If a pump has been installed wrong and the engine does not run in a normal way, put a steel plate over the air inlet opening as shown to stop the engine.

Checking The Plunger And Lifter Washer On An Injection Pump

Check timing dimension for the fuel injection pumps. Make an adjustment if necessary, with the pump housing off the engine. When an adjustment to the timing dimension is done correctly, fuel injection in the cylinder will be at the correct time. If the timing dimension is too small, fuel injection will be early. If the timing dimension is too large, fuel injection will be late.

An injection pump can have a good fuel flow coming from it but not be a good pump because of slow timing that is caused by wear on the bottom end of the plunger. When making a test on a pump that has been used for a long time, use a micrometer and measure the length of the plunger. If the length of the plunger is shorter than the minimum length (worn) dimension given in the chart, install a new pump.

Look for wear at the top part of the plunger. Check the operation of the plunger according to the instructions for the Fuel Injection Test Bench.



Wear Between Lifter Washer And Plunger
Fig. A shows the contact surfaces of a new pump plunger and a new lifter washer. In Fig. B the pump plunger and lifter washer have worn a large amount. Fig. C shows how the flat end of a new plunger makes bad contact with a worn lifter washer, causing rapid wear to both parts.

When there is too much wear on the pump plunger, the lifter washer may also be worn and there will not be good contact between the two parts. To stop fast wear on the end of a new plunger, install new lifters in the place of lifters that have washers with wear.

Fuel Injection Lines

Fuel from the fuel injection pumps is sent through the fuel injection lines to the fuel injection nozzle.

Each fuel injection line of an engine has a special design and must be installed in a certain location. When fuel injection lines are removed from an engine, put identification marks or tags on the fuel lines as they are removed, so they can be put in the correct location when they are installed.

The nuts that hold a fuel injection line to an injection nozzle and injection pump must be kept tight. Use a torque wrench and the 2P5494 Crow Foot Wrench to tighten the fuel line nuts to 40 ± 7 N·m (30 ± 5 lb ft).

Fuel Bypass Valve

The fuel bypass valve controls fuel pressure to the fuel injection pump at full speed to a pressure of 230 ± 35 kPa (33 ± 5 psi).

Finding Top Center Compression Position For No. 1 Piston

NOTE: No. 1 piston at top center (TC) on the compression stroke is the starting point for all timing procedures.



Locating Top Center (Right Side Of Engine)

(1) Timing bolt (in storage location).
(2) Plug.
(3) Bolt.
(4) Cover.

1. Remove timing bolt (1), bolt (3) and cover (4).

2. Remove plug (2).



Location For 9S9082 Engine Turning Tool

(1) Timing bolt installed.
(5) 9S9082 Engine Turning Tool.

3. Install 9S9082 Engine Turning Tool (5) in the housing.

4. Hold timing bolt (1) against the flywheel through the hole from which plug (2) was removed.

5. Use a 1/2 inch drive ratchet and 9S9082 Engine Turning Tool (5) to turn the flywheel counterclockwise (as seen from the rear of the engine). Stop when the timing bolt goes into a threaded hole in the flywheel. If the timing bolt can be turned freely in the threaded hole in the flywheel, the No. 1 piston of the engine is on top center.

NOTE: If the hole in the flywheel is turned beyond the hole in the flywheel housing, turn the flywheel back (clockwise) a minimum of 30 degrees. Do Step 5 again. This will prevent timing error caused by play in the timing gears.


3408C Cylinder And Valve Location


3412C Cylinder And Valve Location

6. Remove the left front valve cover. Look at the valves of No. 1 cylinder. All the valves (inlet and exhaust) will be closed if No. 1 piston is on the compression stroke. You should be able to move the rocker arms up and down with your hand. If No. 1 piston is not on the compression stroke, do the steps that follow.

7. Remove the timing bolt from the flywheel.

8. Turn the flywheel 360 degrees counterclockwise and install the timing bolt.

NOTE: If the hole in the flywheel is turned beyond the hole in the flywheel housing, turn the flywheel back (clockwise) a minimum of 30 degrees. Do Step 5 again. This will prevent timing error caused by play in the timing gears.

Checking Engine Timing And Automatic Timing Advance Unit With 8T5300 Timing Indicator Group And 8T5301 Diesel Timing Adapter Group



8T5300 Timing Indicator Group

(1) 8T5250 Engine Timing Indicator.
(2) 5P7366 Cable Assembly.
(3) 6V2197 Magnetic Transducer.
(4) 5P7362 Cable.
(5) 6V2199 & 6V3093 Transducer Adapters.
(6) 8K4644 Fuse.

The 8T5300 Timing Indicator Group with an 8T5301 Diesel Timing Adapter Group, can be used to measure fuel injection timing for the engine.



8T5301 Diesel Timing Adapter Group

(7) 5P7437 Adapter.
(8) 6V2198 Cable.
(9) 5P7436 Adapter.
(10) 6V7910 Transducer.
(11) 5P7435 Adapter.
(12) 6V3016 Washer.

When checking the dynamic timing on an engine that has a mechanical advance, Caterpillar recommends that a service technician calculate and plot the dynamic timing specifications first on a worksheet like SEHS8140. See Special Instruction, SEHS8580 for information required to calculate the timing curve. For the correct timing specifications to use, see the Engine Information Plate for the performance specification number and make reference to the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche.

NOTE: For more information on acceptable tolerances for dynamic fuel injection timing, see Service Magazine dated 4-1-85 and 10-25-85.

After the timing values are calculated and plotted, the dynamic timing should be checked with the 8T5300 Engine Timing Indicator Group. The engine must be operated from 1000 rpm (base rpm) to high idle and from high idle to 1000 rpm (base rpm). Unstable readings are often obtained below 1000 rpm. Record the dynamic timing at each 100 rpm and at the specified speeds during both acceleration and deceleration. Plot the results on the worksheet.

Inspection of the plotted values will show if the fuel injection timing is within specification and if it is advancing correctly.

1. Make reference to Special Instructions, SEHS8580 for complete instructions and calibration of the 8T5300 Engine Timing Indicator Group.

------ WARNING! ------

The engine must be stopped before the timing indicator group is installed. A high pressure fuel line must be disconnected and a probe must be installed in the flywheel housing.

--------WARNING!------



Transducer In Position

(10) 6V7910 Transducer.
(13) Fuel injection line (for No. 1 cylinder).

2. Disconnect fuel injection line (13) for No. 1 cylinder. Slide the nut up and out of the way. Put 5P7436 Adapter (9) in its place and turn the adapter onto the fuel pump bonnet until the top of the bonnet threads are approximately even with the bottom of the "window" in 5P7436 Adapter (9).

3. Put 5P7435 Adapter (11) on 6V7910 Transducer (10) and put the end of 5P7435 Adapter (11) in the "window" of 5P7436 Adapter (9).

4. Move the end of fuel injection line (13) down on top of 5P7435 Tee Adapter (11). Hold fuel injection line (13) in place with 5P7437 Adapter (7) and tighten to a torque of 40 N·m (30 lb ft).



Timing Hole Location

(14) Plug.

5. Remove plug (14) from timing hole in flywheel housing. Install 6V2199 or 6V3093 Transducer Adapter (5) into the timing hole and tighten just a small amount more than finger tight.



Transducer In Position

(3) 6V2197 Magnetic Transducer.

6. Push 6V2197 Magnetic Transducer (3) into 6V2199 or 6V3093 Transducer Adapter (5) until it makes contact with the flywheel. Pull it back out 1.5 mm (.06 in) and finger tighten the knurled locknut.

7. Connect the cables from the transducer to engine timing indicator (1). Calibrate and make adjustments. For calibration procedure, refer to Special Instruction SEHS8580.

8. Start the engine and let it reach operating temperature. Then run the engine at approximately one half throttle for eight to ten minutes before measuring timing.

9. Run the engine at the rpm required to check low idle, high idle and the automatic timing advance. Record the engine timing indicator readings. If the engine timing is not correct, refer to Fuel System Adjustments: On Engine, Camshaft Timing For The Fuel Injection Pump for static adjustment of the fuel injection pump drive.

10. If the timing advance is not correct, or if the operation of the advance is not even, repair or replace the automatic timing advance. The automatic timing advance cannot be adjusted.

Fuel System Adjustments: On Engine

Camshaft Timing For The Fuel Injection Pump

1. Put No. 1 piston at top center (TC) on the compression stroke. Refer to Finding Top Center Compression Position For No. 1 Piston.

NOTE: A 1P3566 9/16 Hex Bit cut to a length of 25 mm (1.0 in) can be used to remove the plug from the front end of the fuel injection pump housing.



Timing Pin Installed

(A) 6V6019 Timing Pin.

2. Remove the plug at the front end of the fuel injection pump housing.

3. Insert the tapered end of the 6V6019 Timing Pin (A) through the hole in the fuel injection pump housing.

4. If the timing is correct, the timing pin will go into the notch in the camshaft and the timing bolt will turn into the threaded hole in the flywheel. If the timing is not correct, the timing must be changed.

NOTE: If the timing is correct, remove the timing pin and the timing bolt.



Access Cover To Automatic Timing Advance Assembly

(1) Cover.

If the timing was not correct, remove the timing pin. Use the follow procedure to change the timing:

a. Remove the access cover (1) to the four bolts of the automatic timing advance.



Automatic Timing Advance Assembly

(2) Bolts.
(3) Automatic timing advance.
(4) Retainer.

b. Be sure that the timing pin is removed before you loosen the bolts. Loosen the four bolts (2) which hold the automatic timing advance (3) on the fuel injection pump camshaft.

c. Tighten the bolts (2) with your fingers until a small amount of resistance to turning the bolts occur. The retainer (4) should push firmly against the automatic timing advance (3). This force will hold the automatic timing advance against the timing gears which prevents play (backlash) when the gears are turned to the correct position.

d. Remove the timing bolt. Turn the flywheel until the timing pin will go into the groove in the fuel injection pump camshaft.

e. With the timing pin inserted, turn the flywheel clockwise (opposite the direction of normal engine rotation) a minimum of 30 degrees. This step makes sure that the backlash is removed from the timing gears when the engine is put on top center (TC).

f. Turn the flywheel in the direction of normal engine rotation until the No. 1 piston of the engine is on top center of the compression stroke. Turn the timing bolt into the threaded hole in the flywheel.

g. Tighten the bolts (2) to a torque of 25 N·m (20 lb ft). Then remove the timing pin from the injection pump housing.

h. Tighten the bolts (2) to a torque of 136 ± 7 N·m (100 ± 5 lb ft). Then remove the timing bolt from the flywheel.

5. Turn the crankshaft two complete revolutions. Check the timing again to see that timing pin will go into the notch in the camshaft with the bolt in the flywheel.

6. If the timing is not correct, repeat Steps b thru h.

NOTE: If the timing bolt is correct, remove the timing pin and the timing bolt.

Measuring Fuel Injection Pump Timing Dimension

1. Put the No. 1 piston at top center (TC) on the compression stroke. Refer to Finding Top Center Compression Position For No. 1 Piston.

2. Remove the plug at the front end of the fuel injection pump housing.



Timing Pin Installed

(A) 6V6019 Pin.

3. Insert the tapered end of the 6V6019 Pin (A) through the hole in the fuel injection pump housing. The timing pin must fit into the notch in the fuel injection pump camshaft.

NOTE: If No. 1 piston is at top center of compression stroke and the 6V6019 Pin does not fit in the notch in the pump camshaft, refer to Camshaft Timing For The Fuel Injection Pump.

4. Before any fuel injection pump can be removed, the fuel racks must be put in the center position. Reference to Removal Of Fuel Injection Pump.



Tooling Setup For Measuring The Timing Dimension

(1) 8S3158 Dial Indicator.
(2) 3P1565 Collet Clamp.
(3) 5P4156 Indicator Base.
(4) 5P4158 Gauge.
(5) 5P4163 Indicator Contact Point.



Check The Timing Dimension (Typical Illustration)

(1) 8S3158 Indicator Gauge Gp.
(3) 5P4156 Indicator Base.
(4) 5P4158 Gauge.

5. Remove No. 1 fuel injection pump with the 8T5287 Wrench and the 8S2244 Pump Extractor. Put the 5P4158 Gauge (4) into the bore in the fuel injection pump housing.

6. Put the 3P1565 Collet Clamp (2) and the 5P4156 Indicator Base (3) on the 8S3158 Indicator Gauge Gp. (1). Put the 5P4163 Indicator Contact Point (5) on the indicator.

Use the following procedure to calibrate the dial indicator before measuring the lifter dimension:

a. Put the 101.6 mm (4.00 in) long 5P4157 Gauge on the 5P4159 Gauge.

b. With the contact point in the gauge hole, put the dial indicator and base on top of the 5P4157 Gauge.

c. Loosen the screw that locks the dial face. Move the dial face until the large pointer is on zero. Tighten the screw.

d. Record the position of the small pointer. The dial indicator is now calibrated.

NOTE: When the fuel injection pump timing dimension is measured, find the difference between the calibrated reading and the present reading on the dial face. A dimension of 101.6 mm (4.00 in) must be added to the difference in indicator readings for the correct measurement.

8. Install the indicator assembly through the 5P4158 Gauge (4).

9. The correct timing dimension using the 8S3158 Indicator Gauge Gp (1) is:

ON ENGINE Timing dimension:

3408C ... 106.017 ± 0.051 mm(4.1739 ± .0020 in)
3412C ... 105.710 ± 0.051 mm(4.1618 ± .0020 in)

NOTE: If the timing dimension is different than the correct timing dimension given above and the camshaft timing for the fuel injection pump is correct, remove the fuel injection pump from the engine in order to check all lifter settings and plunger lengths. Adjust the lifter settings and plunger lengths. Adjust the lifter settings as necessary. Refer to the following tables in the Fuel System Adjustments: Off Engine section of this manual for the correct lifter settings:

* Lifter Settings (3408C)
* Lifter Settings (3412C)

10. If the timing dimension is correct, install the No. 1 fuel injection pump into the bore in the pump housing. Refer to Installation Of Fuel Injection Pump section of this manual.

Fuel Rack Setting



Governor And Injection Pump Housing

(1) Governor control shaft.
(2) Control linkage

1. Disconnect the governor control linkage (2) so that the governor control shaft (1) can move freely through its full travel.

2. Move the governor control shaft (1) to the shutoff position.



Put Rack At Zero Position

(1) Governor control shaft.
(3) Hole.
(4) 6V6019 Timing Pin.

3. Remove the plug from hole (3). Put the 6V6019 Timing Pin (4) in the hole (3) with the flat end down.

4. Turn the governor control shaft (1) toward High Idle. Push down on the 6V6019 Timing Pin (4) until the timing pin engages in the slot (groove) in the rack. The rack is now centered at zero position.

5. Remove the plug at the rear of the housing.



Check Rack Setting

(5) Brass terminal.
(6) Fuel ratio control (if equipped).
(7) 6V3075 Dial Indicator.
(8) 8T0500 Continuity Test Light.

6. Put the 3P1565 Collet Clamp and the 6V3075 Dial Indicator (7) with the 9S8883 Indicator Contact Point in the hole at the rear of the housing.

7. Adjust the indicator to "0" (zero). Tighten the nut of the collet to hold the indicator at the zero position.

8. Remove the 6V6019 Pin (4).

9. Connect the clip end of the 8T0500 Continuity Test Light (8) to the brass terminal (5) on the governor housing. Connect the other end of the tester to an electrical ground.



Adjustment To The Rack Setting (Typical Example)

(9) 8T9173 Governor Adjusting Tool Gp.
(10) Adjustment screw.
(11) Locknut.
(12) Stop collar.

10. Turn the governor control shaft (1) in the FUEL ON direction until the light in the tester shows a maximum output. Turn the shaft in the FUEL OFF direction until the test light goes out. Turn the shaft slowly in the FUEL ON direction until the test light has a minimum light output. In this position, the rack stop collar (12) just starts to make contact with the torque spring.

11. Read the fuel rack setting dimension directly from the dial indicator. See the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche, or look at the Engine Information Plate installed on the engine, in order to find the correct measurement for the rack setting.

12. If adjustment of the fuel rack setting is needed, remove the cover from the top of the governor. Use the 8T9173 Governor Adjusting Tool Gp (9) to loosen the locknut (10). Turn the adjustment screw (10) in a clockwise direction in order to decrease the fuel rack setting. Turn the adjustment screw in a counterclockwise direction in order to increase the fuel racking setting.

13. Tighten the locknut (11). Perform Steps 11 and 12 in order to check the correct fuel rack setting.

14. When the fuel rack is correct, use the 8T9173 Governor Adjustment Tool Gp (9) to hold the screw (10). Tighten the locknut (11) to a torque of 12 ± 4 N·m (9 ± 3 lb ft).

15. Install the fuel control on the governor. Connect the governor control linkage.

Fuel System Adjustments: Off Engine

Setting Fuel Injection Pump Dimension

The OFF ENGINE setting adjusts for wear of components in the injection pump housing. Adjustment of the fuel camshaft timing gives compensation for wear in the timing gears and on the camshaft of the fuel injection pumps.

1. Use the 8T5287 Wrench and the 8S2244 Pump Extractor to remove the fuel injection pumps.



6V4180 Lifter Setting Tool Group

(1) 1P7410 Timing Plate.
(2) 5P1768 Indicator.
(3) 5P3601 Adapter As.
(4) 6V6019 Pin
(5) Hard Washer
(6) 0S1617 Bolt



Installation of the 5P1768 Indicator

(2) 5P1768 Indicator
(3) 5P3601 Adapter As.
(7) 2A0762 Bolt.

2. Fasten the 5P1768 Indicator (2) to the fuel injection pump housing with 2A0762 Bolt (7).

3. Install the 5P3601 Adapter As (3) on the drive end of the fuel injection pump camshaft.

4. Install the tapered end of the 6V6019 Pin (4) through the timing hole in the pump housing and into the notch in the camshaft.

5. Put the 1P7410 Timing Plate (1) on the 5P3601 Adapter As (3). Install the 2S6160 Hard Washer (5) and the 0S1617 Bolt (6). Do not tighten the bolt.

6. Turn the 1P7410 Timing Plate (1) until the starting point degree mark on the 1P7410 Timing Plate (1) is aligned with the pointer at zero.

7. Tighten the 0S1617 Bolt (6) to a torque of 25 N·m (20 lb ft).

NOTE: Be sure that the 1P7410 Timing Plate does not move from the starting point degree mark while the bolt is tightened.

8. Remove the 6V6019 Pin (4).

9. Refer to the Lifter Settings (3408C) and Lifter Settings (3412C) tables for the timing plate degrees corresponding to the lifter being checked. Turn the timing plate counterclockwise until the degree setting for the lifter being check is aligned with the pointer.

10. Use the following procedure to calibrate the dial indicator before measuring the lifter dimension:

a. Put the 101.6 mm (4.00 in) long 5P4157 Gauge on the 5P4159 Gauge Stand.

b. With the contact point in the gauge hole, put the dial indicator and base on top of the 5P4157 Gauge.

c. Loosen the screw that locks the dial face. Move the dial face until the large pointer is on zero. Tighten the screw.

d. Record the position of the small pointer. The dial indicator is now calibrated.



Tooling Setup For Measuring The Timing Dimension

(8) 8S3158 Indicator Gauge Gp.
(9) 3P1565 Collet Clamp.
(10) Indicator Base
(11) 5P4158 Gauge.
(12) Spacer.
(13) Timing dimension.
(14) 5P4163 Indicator Contact Point.

NOTE: When measurement of the fuel injection pump timing dimension is made, find the difference between the calibration reading and the present reading on the dial face. A dimension of 101.6 mm (4.00 in) must be added to the difference in indicator readings for the correct measurement.

11. The OFF ENGINE timing dimension for adjustment of each lifter is:

OFF ENGINE Timing dimension ... 110.335 ± 0.051mm(4.3439 ± .0020 in)

12. The spacer (12) of each injection pump must be selected to change the timing dimension of that fuel injection pump. Refer to the Spacer Table for the spacer thickness of each space part number.

13. Perform another check of all timing dimensions after all adjustments have been made.

14. Refer to Installation Of Fuel Injection Pump section of this manual for the correct procedures for the installation of fuel injection pumps in the housing and to check the full travel of the fuel racks.

15. After the fuel injection pump is installed on the engine, perform the procedures in Fuel System Adjustments: On Engine for Camshaft Timing For The Fuel Injection Pump and for Measuring Fuel Injection Pump Timing Dimension.

Engine Speed Measurement


9U7400 Multitach Tool Gp

The 9U7400 Multitach Tool Gp is used to check the fan speed. Refer to Operator's Manual, NEHS0605, for the operating instructions for this tool.

Governor Adjustments


NOTICE

A mechanic with training in governor adjustments is the only one to make the adjustment to the set point rpm.


Engine rpm must be check with an accurate tachometer. Make reference to Engine Speed Measurement.

Low Idle Adjustment

NOTE: The correct Low Idle rpm is given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche.

------ WARNING! ------

To help prevent an accident caused by parts in rotation, work carefully around an engine that has been started.

--------WARNING!------

Start the engine and run until the temperature of normal operation is reached. Check low idle rpm with no load on the engine. If an adjustment is necessary, use the procedure that follows:

1. Remove the sealed cover over the High and Low Idle adjustment screws.



Idle Adjustment

(1) Adjustment screw (for high idle).
(2) Adjustment screw (for low idle).
(3) Tachometer drive.

2. To adjust the Low Idle rpm, move the governor control to Low Idle position and turn adjustment screw (2). Increase the engine speed and then return control back to Low Idle position to check the setting again.

3. When governor adjustment is correct, install the cover over the adjustment screws.

When the cover is installed on the governor, the idle adjustment screws fit into holes in the cover. The shape of the holes will not let the idle adjustment screws turn after the idle adjustment is done and the cover is installed.

4. Install a new wire and seal to the cover bolt.

Checking Set Point (Balance Point)

The engine set point is an adjusted specification and is important to the correct operation of the engine. High idle rpm is NOT an adjusted specification. Set point (formerly balance point) is full load rpm plus an additional 20 rpm. Set point is the rpm at which the fuel setting adjustment screw and stop or first torque spring just start to make contact. At this rpm, the fuel setting adjustment screw and stop or first torque spring still have movement between them. When additional load is put on the engine, the fuel setting adjustment screw and stop or first torque spring will become stable against each other. Set point is controlled by the fuel setting and the high idle adjustment screw.


9U7400 Multitach Tool Gp

The 9U7400 Multitach Tool Gp is used to check the set point. Refer to Operator's Manual, NEHS0605, for the operating instructions for this tool.

NOTE: Do not use the tachometer unless its accuracy is known to be within ± 1 rpm.

If the set point is correct and the high idle speed is within specifications, the fuel system operation of the engine is correct. The set point for the engine is:

A. At 20 rpm greater than full load speed.

B. The rpm where the fuel setting adjustment screw stop or first torque spring just make contact.

Use the procedure that follows to check the set point. Make reference to Techniques For Loading Engines in Special Instruction SEHS7050.

1. Connect a tachometer which has good accuracy to the tachometer drive.



Circuit Tester Installed

(1) Brass terminal screw.
(2) 8T0500 Continuity Test Light.

2. Connect the clip end of the 8T0500 Continuity Test Light to the brass terminal screw (1) on the governor housing. Connect the other end of the tester to a place on the fuel system which is a good ground connection.

------ WARNING! ------

Work carefully around an engine that is running. Engine parts that are hot, or parts that are moving, can cause personal injury.

--------WARNING!------

3. Start the engine.

4. With the engine at normal conditions for operation, run the engine at high idle.

5. Make a record of the speed of the engine at high idle.

6. Add load on the engine slowly until the circuit tester light just comes on (minimum light output). This is the set point.

7. Make a record of the speed (rpm) at the set point.

8. Repeat Step 6 several times to make sure that the reading is correct.

9. Stop the engine. Make a comparison of the records from Steps 5 and 7 with Full Load Speed from the Engine Information Plate. If the Engine Information Plate is not available, see the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche. The tolerance for the set point is ± 10 rpm. The tolerance for the high idle rpm is ± 50 rpm in chassis and ± 30 rpm on a bare engine. If the readings from Steps 5 and 7 are within the tolerance, no adjustment is needed.

NOTE: Engines have the actual Dyno High Idle stamped on the Engine Information Plate. It is possible, in some applications that the high idle rpm will be less than the actual lower limit. This can be caused by high parasitic loads such as hydraulic pumps, compressors, etc.

Adjusting Set Point (Balance Point)

1. If the set point and the high idle rpm are within tolerance, no adjustment is to be made.

2. If the set point rpm is not correct, remove the sealed cover over the High and Low Idle adjustment screws.



Set Point Adjustment

(1) Adjustment screw (for high idle).
(2) Adjustment screw (for low idle).
(3) Tachometer drive.

3. Turn adjustment screw (1) to adjust the set point to the midpoint of the tolerance.

4. When the set point is correct, check the high idle rpm. The high idle rpm must not be more than the high limit of the tolerance.

If the high idle rpm is more than the high limit of the tolerance, check the governor spring and flyweights. If the high idle rpm is less than the low limit of the tolerance, check for excess parasitic loads and then the governor spring and flyweights.

5. When governor adjustment is correct, install the cover over the adjustment screws.

When the cover is installed on the governor, the idle adjustment screws fit into holes in the cover. The shape of the holes will not let the idle adjustment screws turn after the idle adjustment is done and the cover is installed.

6. Install a new wire and seal to the cover bolt.

Air Inlet And Exhaust System

Restriction Of Air Inlet And Exhaust

There will be a reduction of horsepower and efficiency of the engine if there is a restriction in the air inlet or exhaust system.

Air flow through the air cleaner must not have a restriction (negative pressure difference measurement between atmospheric air and air that has gone through air cleaner) of more than 7.47 kPa (30 inches of H2O).

Back pressure from the exhaust (pressure difference measurement between exhaust at outlet elbow and atmospheric air) must not be more than 6.72 kPa (27 inches of H20).

Measurement Of Pressure In Inlet Manifold

The efficiency of an engine can be checked by making a comparison of the pressure in the inlet manifold with the information given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche. This test is used when there is a decrease of horsepower from the engine, yet there is no real sign of a problem with the engine.

The correct pressure for the inlet manifold is given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche. Development of this information is done with these conditions:

a. 99 kPa (29.7 inches of Hg) barometric pressure.

b. 29°C (85°F) outside air temperature.

c. 35 API rated fuel

Any change from these conditions can change the pressure in the inlet manifold. Outside air that has higher temperature and lower barometric pressure than given above will cause a lower horsepower and a lower inlet manifold pressure measurement than given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche. Outside air that has a lower temperature and a higher barometric pressure will cause higher horsepower and a higher inlet manifold pressure measurement.

A difference in fuel rating will also change horsepower and the pressure in the inlet manifold. If the fuel is rated above 35 API, pressure in the inlet manifold can be less than given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche. If the fuel is rated below 35 API, the pressure in the inlet manifold can be more than given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche. Be Sure That The Air Inlet And Exhaust Do Not Have A Restriction When Making A Check Of Pressure In The Inlet Manifold.



Plug For Pressure Test

(A) Plug.
(B) Exhaust elbow.
(C) Pipe to inlet manifold.

Use the 1U5470 Engine Pressure Group to check the pressure in the inlet manifold.

Remove plug (A) on inlet pipe to measure inlet manifold pressure.


1U5470 Engine Pressure Group

This tool group has a indicator to read pressure in the inlet manifold. Special Instruction SEHS8907 is with the tool group and gives instructions for its use.

Turbocharger

If any unusual sound or vibration in the turbocharger is noticed, a quick check of bearing condition can be made without disassembling the turbocharger. This can be done by removing the piping from the turbocharger and inspecting the compressor impeller, turbine wheel and compressor cover. Rotate the compressor and turbine wheel assembly by hand and observe by feeling excess end play. The rotating assembly should rotate freely with no rubbing or binding. If there is any indication of the impeller rubbing the compressor cover or the turbine wheel rubbing the turbine housing, recondition the turbocharger or replace with a new or rebuilt one.

End clearance is best check with a dial indicator. Attach a dial indicator with the indicator point on the end of the shaft. Move the shaft from end to end making not of the total indicator reading.

If end play is more than the maximum end play allowable, rebuild or replace the turbocharger. End play less than the minimum end play allowable could indicate carbon build up on the turbine wheel and the turbocharger should be disassembled for cleaning and inspection.


Checking Turbocharger Rotating Assembly End Play (Typical Example)

A more reliable check of bearing conditions can be made only when the turbocharger is disassembled and the bearings, shaft journal and housing bore diameters can actually be measured.

Exhaust Temperature

Use the 1236700 Infrared Thermometer II to check exhaust temperature. Operator's Manual, NEHS0630 is with the tool group and gives instructions for the test procedure.

Crankcase (Crankshaft Compartment) Pressure

Pistons or rings that have damage can be the cause of too much pressure in the crankcase. This condition may cause the engine to run rough. There will also be more than the normal amount of fumes (blowby) coming from the crankcase breather. The breather can then become restricted in a very short time, causing oil leakage at gaskets and seals that would normally have leakage. Other sources of blowby can be worn valve guides or turbocharger seal leakage.


8T2700 Blowby/Airflow Indicator

The 8T2700 Blowby/Airflow Indicator is used to check the amount of blowby. The test procedure is in Special Instruction, SEHS8712.

Compression

An engine that runs rough can have a leak at the valves, or have valves that need adjustment. Use the test that follows for a fast and easy method to find a cylinder that has low compression, or does not have good fuel combustion. Find the speed that the engine runs the roughest, and keep the engine at this rpm until the test is finished. Loosen the fuel line nut at a fuel injection pump to stop the flow of fuel to that cylinder. Do this for each cylinder until a loosened fuel line is found that makes no difference in engine performance. Be sure to tighten each fuel line nut after the test before the next fuel line nut is loosened. This test can also be an indication that the fuel injection is wrong, so the cylinder will have to be checked thoroughly. Remove of the head and inspection of the valves and valve seats is necessary to find those small defects that do not normally cause a problem. Repair of these problems is normally done when reconditioning the engine.

Cylinder Head

The cylinder head has valve seal inserts, valve guides and bridge dowels that can be removed when they are worn or have damage. Replacement of these components can be made with the tools that follow.

Valves

Valve removal and installation is easier with use of the 5S1330 Valve Spring Compressor Assembly and 5S1322 Valve Keeper Installer.

Valve Seat Inserts

Tools needed to remove and install the valve seat inserts are in the 6V4805 Valve Seat Extractor Tool Gp. Special Instruction SMHS 7935 gives an explanation for the procedure to remove the valve seat inserts. For easier installation, lower the temperature of the insert before it is installed in the head.

Valve Guides

Tools needed to remove and install the valve guides are the 5P2396 Bushing and 9U7349 Valve Driver. The counterbore in the driver bushing installs the guide to the correct height. Use a 1P7451 Valve Guide Honing Group to make a finished bore in the valve guide after installation of the guide in the head. Special Instruction, SMHS 7526 gives an explanation for this procedure. Grind the valves after the new valve guides are installed.

Checking Valve Guide Bores

Use the 5P3536 Valve Guide Gauge Group to check the bore of the valve guides. Special Instruction, GMG02562 gives complete and detailed instructions for use of the 5P3536 Valve Guide Gauge Group.

Bridge Dowel

Use a 5P0944 Dowel Puller Group with a 5P0942 Extractor to remove the bridge dowels. Install a new bridge dowel with a 5P2406 Dowel Driver. This dowel driver installs the bridge dowel to the correct height.

Bridge Adjustment

When the head is disassembled, keep the bridges with their respective cylinders. Adjustment of the bridge will be necessary after the valves are ground or other reconditioning of the cylinder head is done. The bridge should be checked and/or adjusted each time the valves are adjusted. Use the procedure that follows to make an adjustment to the bridge.


Bridge Adjustment

NOTE: Valves must be fully closed.

1. Put engine oil on the bridge dowel in the cylinder head and in the bore in the bridge.

2. Install the bridge with the adjustment screw toward the exhaust manifold.

3. Loosen the locknut for the adjustment screw and loosen the adjustment screw several turns.

4. Put a force on the bridge with a finger to keep the bridge in contact with the valve stem opposite the adjustment screw.

5. Turn the adjustment screw clockwise until it just makes contact with the valve stem. Then turn the adjustment screw 30 degrees more in a clockwise direction to make the bridge straight on the dowel, and to make compensation for the clearance in the threads of the adjustment screw.

6. Hold the adjustment screw in this position and tighten the locknut to 30 ± 4 N·m (22 ± 3 lb ft).

7. Put engine oil at the point where the rocker arm makes contact with the bridge.

Valve Lash Setting

NOTE: Valve lash is measured between the rocker arm and the bridge for the valves.


Valve Lash

To make an adjustment to the valve hash, use the procedure that follows:


Valve Lash Adjustment

1. Put No. 1 piston at top center (TC) on the compression stroke. Make reference to Finding Top Center Compression Position For No. 1 Piston.

2. Make an adjustment to the valve lash on the inlet valves for cylinders:

3408C 1,2,5,7
3412C 1,3,4,6,7,12

Make an adjustment to the valve lash on the exhaust valves for cylinders:

3408C 1,3,4,8
3412C 1,4,5,8,9,12

3. Loosen the locknut for the push rod adjustment screw and turn the screw counterclockwise to increase the valve lash.

4. Put a feeler gauge of the correct dimension between the rocker arm and bridge contact surface. Turn the adjustment screw clockwise until the valve lash is set to specifications in the chart Valve Lash Setting: Engine Stopped.

5. After each adjustment, tighten the nut for the adjustment screw to a torque of 30 ± 4 N·m (22 ± 3 lb ft) and check the adjustment again.


3408C Cylinder And Valve Location


3412C Cylinder And Valve Location

6. Remove the timing bolt and turn the flywheel 360 degrees in the direction of normal engine rotation. This will put No. 8 piston at top center (TC) on the compression stroke for the 3408C and No. 11 piston at top center (TC) on the compression stroke for the 3412C. Install the timing bolt in the flywheel.

7. Make an adjustment to the valve lash on the inlet valves for cylinders:

3408C 3,4,6,8
3412C 2,5,8,9,10,11

Make an adjustment to the valve lash on the exhaust valves for cylinders:

3408C 2,5,6,7
3412C 2,3,6,7,10,11

8. Loosen the locknut for the push rod adjustment screw and turn the screw counterclockwise to increase the valve lash.

9. Put a feeler gauge of the correct dimension between the rocker arm and bridge contact surface. Turn the adjustment screw clockwise until the valve lash is set to specifications in the chart Valve Lash Setting: Engine Stopped.

10. After each adjustment, tighten the nut for the adjustment screw to a torque of 30 ± 4 N·m (22 ± 3 lb ft) and check the adjustment again.

11. Remove the timing pin from the flywheel after all valve lash adjustments are correct.

Lubrication System

One of the problems in the list that follows will generally be an indication of a problem in the lubrication system for the engine.

Too Much Oil Consumption

Oil Pressure Is Low

Oil Pressure Is High

Too Much Bearing Wear

Increased Oil Temperature

Too Much Oil Consumption

Oil Leakage on Outside of Engine

Check for leakage of the seals at each end of the crankshaft. Look for leakage at the oil pan gasket and all lubrication system connections. Check to see if oil comes out of the crankcase breather. This can be caused by combustion gas leakage around the pistons. A dirty crankcase breather will cause high pressure in the crankcase, and this will cause gasket and seal leakage.

Oil Leakage Into Combustion Area of Cylinders

Oil leakage into the combustion area of the cylinder can be the cause of blue smoke. There are four possible ways for oil leakage into the combustion area of the cylinders:

1. Oil leakage between worn valve guides and valve stems.

2. Worn or damaged piston rings, or dirty oil return holes.

3. Compression ring and/or intermediate ring not installed correctly.

4. Oil leakage past the seal rings in the impeller end of the turbocharger shaft.

Too much oil consumption can also be the result if oil with the wrong viscosity is used. Oil with a thin viscosity can be caused by fuel leakage into the crankcase, or by increased engine temperature.

Measuring Engine Oil Pressure

An oil pressure indicator that has a defect can give an indication of low oil pressure.

The 1U5470 Engine Pressure Group can be used to check engine oil pressure.


1U5470 Engine Pressure Group

This tool group has a indicator to read oil pressure in the engine. Special Instruction, SEHS8524, is with the tool group and gives instructions for the test procedure.

1. Be sure that the engine is filled to the correct level with SAE 10W30 oil. If any other viscosity of oil is used, the information in the Engine Oil Pressure Graph does not apply.

2. Connect the 1U5470 Engine Pressure Group to the main oil manifold at location (1).

3. Operate the engine to get it up to normal operating temperature.



Oil Manifold (Typical Example)

(1) Pressure test location.

4. Keep the oil temperature constant with the engine at its rated rpm, and read the pressure indicator.

NOTE: Make sure engine oil temperature does not go above 115°C (239°F).

5. On the Engine Oil Pressure Graph, find the point that the lines for engine rpm and oil pressure intersect (connect).


Engine Oil Pressure Graph

6. If the results do not fall within the "Acceptable" pressure range given in the graph, find the cause and correct it. Engine failure or a reduction in engine life can be the result if engine operation is continued with oil manifold pressure outside this range.

NOTE: A record of engine oil pressure, kept at regular intervals, can be used as an indication of possible engine problems or damage. If there is a sudden increase or decrease of 70 kPa (10 psi) in oil pressure, even though the pressure is in the "Acceptable" range on the graph, the engine should be inspected and the problem corrected.

Oil Pressure Is Low

Crankcase Oil Level

Check the level of the oil in the crankcase. Add oil if needed. It is possible for the level to be too far below the engine oil pump supply tube. This will cause the engine oil pump to not have the ability to supply enough lubrication to the engine components.

Engine Oil Pump Does Not Work Correctly

The inlet screen of the supply tube for the engine oil pump can have a restriction. This will cause cavitation (low pressure bubbles suddenly made in liquids by mechanical forces) and a loss of oil pressure. Air leakage in the supply side of the engine pump will also cause cavitation and loss of oil pressure. If the bypass valve for the engine pump is held in the open (unseated) position, the lubrication system can not get to maximum pressure. Engine oil pump gears that have too much wear will cause a reduction in oil pressure.

Oil Filter Bypass Valves

If the bypass valve for the engine oil filter is held in the open position (unseated) because the engine oil filter has a restriction, a reduction in oil pressure can result. To correct this problem, remove and clean the bypass valve and bypass valve bore. Install a new engine oil filter to be sure that no more debris makes the bypass valve stay open.

Too Much Clearance At Engine Bearings Or Open Lubrication System (Broken Or Disconnected Oil Line Or Passage)

Components that are worn and have too much bearing clearance can cause oil pressure to be low. Low oil pressure can also be caused by an oil line or oil passage that is open, broken or disconnected.

Piston Cooling Tubes (Jets)

When engine is operated, cooling jets direct oil toward the bottom of the piston to lower piston and ring temperatures. If there is a failure of one of the jets, or it is bent in the wrong direction, seizure of the piston will be caused in a very short time.

Use the 5P8709 Piston Tool Group to check and adjust the alignment of piston cooling jets.

Oil Pressure Is High

Oil pressure will be high if the bypass valve for the engine oil pump can not move from the closed position.

Too Much Bearing Wear

When some components of the engine show bearing wear in a short time, the cause can be a restriction in an oil passage. A broken oil passage can also be the cause.

If the indicator for oil pressure shows enough oil pressure, but a component is worn because it can not get enough lubrication, look at the passage for oil supply to the component. A restriction in a supply passage will not let enough lubrication get to a component, and this will cause early wear.

Increased Oil Temperature

Look for a restriction in the oil and coolant passages of the engine oil cooler. If the engine oil cooler has a restriction, the oil temperature will be higher than normal when the engine is operated. The oil pressure of the engine will not get low just because the engine cooler has a restriction.

Also check the oil engine cooler bypass valve to see if it is held in the open position (unseated). This condition will let the oil through the valve instead of the engine oil cooler, and oil temperature will increase.

Cooling System

This engine has a pressure type cooling system. A pressure type cooling system gives two advantages. The first advantage is that the cooling system can have safe operation at a temperature that is higher than the normal boiling (steam) point of water. The second advantage is that this type system prevents cavitation (low pressure bubbles suddenly made in liquids by mechanical forces) in the water pump. With this type system, it is more difficult for an air or steam pocket to be made in the cooling system.

The cause for increased engine temperature is generally because regular inspections of the cooling system were not made. Make a visual inspection of the cooling system before a test is made with test equipment.

Visual Inspection Of The Cooling System

1. Check coolant level in the cooling system.

2. Look for leaks in the system.

NOTE: Water pump seals. A small amount of coolant leakage across the surface of the "face-type" seals is normal, and required, to provide lubrication for this type of seal. A hole is provided in the water pump housing to allow this coolant/seal lubricant to drain from the pump housing. Intermittent leakage of small amounts of coolant from this hole is not an indication of water pump seal failure. Replace the water pump seals only if a large amount of leakage, or a constant flow of coolant is observed draining from the water pump housing.

3. Look for bent radiator fins. Be sure that air flow through the radiator does not have a restriction.

4. Inspect the drive belts for the fan.

5. Check for damage to the fan blades.

6. Look for air or combustion gas in the cooling system.

7. Inspect the filler cap and the surface that seals the cap. This surface must be clean.

Testing The Cooling System

Remember that temperature and pressure work together. When a diagnosis is made of a cooling system problem, temperature and pressure must both be checked. Cooling system pressure will have an effect on cooling system temperatures. For an example, look at the chart to see the effect of pressure and height above sea level on the boiling (steam) point of water.

Test Tools For Cooling System


4C6500 Digital Thermometer

The 4C6500 Digital Thermometer is used in the diagnosis of overheating (engine hotter than normal) or overcooling (engine cooler than normal) problems. This group can be used to check temperatures in several different parts of the cooling system. The testing procedure is in Operating Manual, NEHS0554.


8T2700 Blowby/Air Flow Indicator Group

The 8T2700 Blowby/Air Flow Indicator Group is used to check the air flow through the radiator core. The test procedure is in Special Instruction, SEHS8712.


9U7400 Multitach Tool Gp

The 9U7400 Multitach Tool Gp is used to check the fan speed. Refer to Operator's Manual, NEHS0605, for the operating instructions for this tool.


9S8140 Pressurizing Pump

The 9S8140 Pressurizing Pump is used to test pressure caps and to pressure check the cooling system for leaks.

------ WARNING! ------

DO NOT loosen the filler or pressure cap on a hot engine. Steam or hot coolant can cause severe burns.

--------WARNING!------

Filler Cap and Pressure Relief Valve



Typical Pressure Relief Valve System

(1) Pressure relief valve.
(2) Stud for filler cap.

The 9S8140 Pressurizing Pump is used to test pressure relief valves and to pressure check the cooling systems for leaks.



9S8140 Pressurizing Pump

(3) Release valve.
(4) Adapter.
(5) Hose.

One cause for a pressure loss in the cooling system can be a bad seal on the radiator filler cap.

------ WARNING! ------

DO NOT loosen the filler cap or pressure cap on a hot engine. Steam or hot coolant can cause severe burns.

--------WARNING!------

1. After the engine is cool, loosen the filler cap and let the pressure out of the cooling system. Then remove the filler cap.

2. Inspect the filler cap carefully. Look for damage to the seal or to the surface that seals. Any foreign material or deposits on the cap, seal or surface that seals, must be removed.

Use the procedure that follows to pressure check the cooling system.

1. Make sure the coolant level is above the top of the radiator core.

2. Install and tighten the filler cap.

3. Remove hose (5) from adapter (4).

4. Remove the pressure test plug for the radiator top tank.

5. Install the end of hose (5) in the hole for the pressure test plug as shown.

6. Operate the pump until the pointer on the pressure indicator no longer increases. The highest pressure indication on the indicator is the point that the relief valve opens. The correct pressure that makes the relief valve open is 105 to 125 kPa (15 to 18 psi).

7. If the relief valve does not open within pressure specification, replacement of the relief valve is necessary.

8. If the relief valve is within specifications, check the radiator for outside leakage.


9S8140 Pressurizing Pump installed

9. Check all connections and hoses of the cooling system for outside leakage.

10. If you do not see any outside leakage and the pressure reading on the indicator is still the same after five minutes, the radiator and cooling system does not have leakage. If the reading on the indicators goes down and you do not see any outside leakage, there is leakage on the inside of the cooling system. Make repairs as necessary.

------ WARNING! ------

If a pressure indication is shown on the indicator, to avoid personal injury push release valve (3) to release all pressure in the system before removal of hose (5) from the radiator.

--------WARNING!------

11. Remove hose (5) from radiator test pressure location.

12. Install plug in pressure test location.

Indicator For Water Temperature



Water Temperature Connection

(1) Sending unit.

If the engine gets too hot and a loss of coolant is a problem, a pressure loss in the cooling system could be the cause. If the indicator for water temperature shows that the engine is getting too hot, look for coolant leakage. If a place cannot be found where there is coolant leakage, check the accuracy of the indicator for water temperature. A temperature indicator of known accuracy can be connected at the location for sending unit (1) to make this check. Also, the 4C6500 Digital Thermometer or the 2F7112 Thermometer and 6B5072 Reducing Bushing can be used.

------ WARNING! ------

Work carefully around an engine that is running. Engine parts that are hot, or parts that are moving, can cause personal injury.

--------WARNING!------

Start the engine and run it until the temperature is at the desired range according to the test indicator or thermometer. If necessary, put a cover over part of the radiator or cause a restriction of the coolant flow. The reading on the indicator for water temperature must be the same as the test indicator or thermometer within the tolerance range in the chart in Specifications, 3408C & 3412C Marine Engines, SENR1131.

Water Temperature Regulators

1. Remove the regulator from the engine.

2. Heat water in a pan until the temperature is 92°C (197°F). Move the water around in the pan to make it all the same temperature.

3. Hang the regulator in the pan of water. The regulator must be below the surface of the water and it must be away from the sides and bottom of the pan.

4. Keep the water at the correct temperature for ten minutes.

5. After ten minutes, remove the regulator and immediately measure the distance the regulator has opened. The distance must be a minimum of 10.4 mm (.41 in).

6. If the distance is less than 10.4 mm (.41 in), make a replacement of the regulator.

Basic Block

Piston Rings

This engine has piston grooves and rings of the Keystone (taper) design. The 1U6431 Gage Group is available to check the top two ring grooves in the piston. For correct use of the gage group see the instruction card that is with the gage group.

Connecting Rods And Pistons

Use the 7M3978 Piston Ring Expander to remove or install piston rings.

Use the 5P3526 Piston Ring Compressor to install pistons into cylinder block.

Tighten the connecting rod bolts in the step sequence that follows:

1. Put engine oil on bolt threads and contact surfaces of nut and cap.

2. Tighten all bolts to 80 ± 8 N·m (60 ± 6 lb ft).

3. Put a mark on each nut and end of bolt.

4. Tighten each nut 120 ± 5 degrees from the mark.

The connecting rod bearings fit tightly in the bore in the rod. If bearing joints or backs are worn (fretted), check bore size. This can be an indication of wear because of a loose fit.

Connecting Rod And Main Bearings

Connecting rod bearings are available with 0.64 mm (.025 in) and 1.27 mm (.050 in) smaller inside diameter than the original size bearings. These bearings are for crankshafts that have been "ground" (made smaller than the original size).

Main bearings are available with a larger outside diameter than the original size bearings. These bearings are for cylinder blocks that have had the bore for the main bearings "bored" (made larger than the original size). The size available is 0.64 mm (.025 in) larger outside diameter than the original size bearings.

Cylinder Block


1P3537 Dial Bore Gauge Group

The bore in the block for main bearings can be checked with the main bearing caps installed without bearings. Tighten the nuts that hold the caps to the torque shown in the Specifications module. Alignment error in the bores must not be more than 0.08 mm (.003 in). Special Instruction, SMHS7606 gives instructions for the use of 1P4000 Line Boring Tool Group for alignment of the main bearing bores. The 1P3537 Dial Bore Gauge Group can be used to check the size of the bores. Special Instruction, GMG00981 is with the group.

Cylinder Liner Projection


(1) Bolt.
(2) Steel washer.
(3) Fabric washer.

Install larger diameter washers (4) and (5) under bolts marked "X".

Install smaller diameter washers (6) and (7) under remaining two bolts.



Quantity of six each required for one cylinder on any engine, except where noted.

1. Install clean liners or cylinder packs (without the filler band or the rubber seals), spacer plate gasket and clean spacer plate.

2. Install bolts and washers, as indicated previously, in the holes. Install all bolts or the six bolts around the liner. Tighten the bolts to a torque of 95 N·m (70 lb ft).

3. Use the 8T0455 Liner Projection Tool Group to measure liner projection at positions indicated with an A,B,C and D. Record measurements for each cylinder. Add the four readings for each cylinder and divide by four to find the average.

4. The cylinder liner specifications are as follows:

Liner projection ... 0.025 to 0.152mm(.0010 to .0060 in)
Maximum variation in each cylinder ... 0.051 mm(.0020 in)
Maximum average variation between adjacent cylinders ... 0.051 mm(.0020 in)
Maximum variation between all cylinders ... 0.102 mm(.0040 in)

5. If the liner projections are out of specification, try rotating the liner or install the liner in another bore to see if the measurements improve.

6. If the liner projections are all below the specifications or low in the range, 0.025 mm (.0010 in) or 0.051 mm (.0020 in), try using a thinner spacer plate. These plates are 0.076 mm (.0030 in) thinner than the regular plate and they will increase the liner projection, thus increasing the fire ring crush. Use these spacer plates to compensate for low liner projections that are less than 0.076 mm (.0030 in) or if the inspection of the top deck reveals no measurable damage directly under the liner flanges, but the average liner projection is less than 0.076 mm (.0030 in).

NOTE: Do not exceed the maximum liner projection of 0.152 mm (.0060 in). Excessive liner projection will contribute to liner flange cracking.

7. With the proper liner projection, mark the liners in the proper position and set them aside.

8. When the engine is ready for final assembly, the O-ring seals, cylinder block and upper filler band must be lubricated before installation. Refer to the Disassembly And Assembly Manual for the proper procedure to install the cylinder liners.

Flywheel And Flywheel Housing

Face Run Out (Axial Eccentricity) Of The Flywheel Housing

If any method other than given here is used, always remember bearing clearance must be removed to get correct measurements.


8T5096 Dial Indicator Group Installed

1. Fasten a dial indicator to the crankshaft flange so the anvil of the indicator will touch the face of the flywheel housing.

2. Put a force on the crankshaft toward the rear before the indicator is read at each point.

3. With dial indicator set at 0.00 mm (.000 in) at location (A), turn the crankshaft and read the indicator at locations (B), (C) and (D).

4. The difference between lower and higher measurements taken at all four points must not be more than 0.38 mm (.015 in), which is the maximum permissible face runout (axial eccentricity) of the flywheel housing.

Bore Runout (Radial Eccentricity) Of The Flywheel Housing

1. Fasten the dial indicator as shown so the anvil of the indicator will touch the bore of the flywheel housing.


8T5096 Dial Indicator Group Installed

2. With the dial indicator in position at (C), adjust the dial indicator to "0" (zero). Push the crankshaft up against the top of the bearing. Write the measurement for bearing clearance on line 1 in column (C).

NOTE: Write the dial indicator measurements with their positive (+) and negative (-) notation (signs). This notation is necessary for making the calculations in the chart correctly.

3. Divide the measurement from Step 2 by 2. Write this number on line 1 in columns (B) & (D).

4. Turn the crankshaft to put the dial indicator at (A). Adjust the dial indicator to "0" (zero).

5. Turn the crankshaft counterclockwise to put the dial indicator at (B). Write the measurement in the chart.

6. Turn the crankshaft counterclockwise to put the dial indicator at (C). Write the measurement in the chart.

7. Turn the crankshaft counterclockwise to put the dial indicator at (D). Write the measurement in the chart.

8. Add lines I & II by columns.

9. Subtract the smaller number from the larger number in line III in columns (B) & (D). The result is the horizontal eccentricity (out of round). Line III, column (C) is the vertical eccentricity.



Graph For Total Eccentricity

(1) Total vertical eccentricity [mm(in)].
(2) Total horizontal eccentricity [mm (in)].
(3) Acceptable.
(4) Not Acceptable.

10. On the graph for total eccentricity find the point of intersection of the lines for vertical eccentricity and horizontal eccentricity.

11. If the point of intersection is in the range marked "Acceptable", the bore is in alignment. If the point of intersection is in the range marked "Not Acceptable", the flywheel housing must be changed.

Face Runout (Axial Eccentricity) Of The Flywheel

1. Install the dial indicator as shown. Always put a force on the crankshaft in the same direction before the indicator is read so the crankshaft end clearance (movement) is always removed.

2. Set the dial indicator to read 0.0 mm (.00 in).

3. Turn the flywheel and read the indicator every 90 degrees.

4. The difference between the lower and higher measurements taken at all four points must not exceed the maximum permissible face runout (axial eccentricity) of the flywheel, as shown in the Flywheel Specification Chart.


Checking Face Runout Of The Flywheel

Bore Runout (Radial Eccentricity) Of The Flywheel



Checking Bore Runout Of The Flywheel

(1) 7H1945 Holding Rod.
(2) 7H1645 Holding Rod.
(3) 7H1942 Dial Indicator.
(4) 7H1940 Universal Attachment.

1. Install the dial indicator (3) and make an adjustment of the universal attachment (4) so it makes contact as shown.

2. Set the dial indicator to read 0.0 mm (.00 in).

3. Turn the flywheel and read the indicator every 90 degrees.

4. The difference between the lower and higher measurements taken at all four points must not exceed the maximum permissible bore runout (radial eccentricity) of the flywheel, as shown in the Flywheel Specification Chart.


Checking Flywheel Clutch Pilot Bearing Bore

5. Runout (eccentricity) of the bore for the pilot bearing for the flywheel clutch, must not exceed the maximum permissible pilot bearing bore runout of the flywheel, as shown in the Flywheel Specification Chart.

Electrical System

Test Tools For Electrical System

Most of the test of the electrical system can be done on the engine. The wiring insulation must be in good condition, the wire and cable connections must be clean and tight, and the battery must be fully charged. If the on-engine test shows a defect in a component, remove the component for more testing.

The service manual Testing & Adjusting Electrical Components, REG00636 has complete specifications and procedures for the components of the starting circuit and the charging circuit.

The 4C4911 Battery Load Tester is a portable unit in a metal case for use under field conditions and high temperatures. It can be used to load test all 6, 8 and 12V batteries. This tester has two heavy-duty load cables that can easily be fastened to the battery terminals. A load adjustment knob on the top permits the current being drawn from the battery to be adjusted to a maximum of 1000 amperes. The tester is cooled by an internal fan that is automatically activated when a load is applied.

The tester has a built in LCD digital voltmeter and amperage meter. The digital voltmeter accurately measures the battery voltage at the battery through tracer wires buried inside the load cables. The digital amperage meter accurately displays the current being drawn from the battery under test.

NOTE: Make reference to Operating Manual, SEHS9249 for more complete information for use of the 4C4911 Battery Load Tester.


8T0900 Ammeter Tool Gp

The 8T0900 Ammeter Tool Gp is a completely portable, self-contained instrument that allows electrical current measurements to be made without breaking the circuit or disturbing the insulation on conductors. A digital display is located on the ammeter for reading current directly in a range from 1 to 1200 amperes. If an optional 6V6014 Cable is connected between this ammeter and one of the digital multimeters, current readings of less than 1 ampere can then be read directly from the display of the multimeter.

A lever is used to open the jaws over the conductor [up to a diameter of 19 mm (.75 in)], and the spring loaded jaws are then closed around the conductor for current measurement. A trigger switch that can be locked in the ON or OFF position is used to turn on the ammeter. When the turn-on trigger is released, the last current reading is held on the display for 5 seconds. This allows accurate measurements to be taken in limited access areas where the digital display is not visible to the operator. A zero control is provided for DC operation, and power for the ammeter is supplied by batteries located inside the handle.

NOTE: Make reference to Special Instruction, SEHS8420 for more complete information for use of the 8T0900 Ammeter Tool Gp.


6V7070 Heavy-Duty Digital Multimeter

The 6V7070 Heavy-Duty Digital Multimeter is a completely portable, hand held instrument with a digital display. This multimeter is built with extra protection against damage in field applications, and is equipped with seven functions and 29 ranges. The 6V7070 Multimeter has an instant ohms indicator that permits continuity checks for fast circuit inspection. It also can be used for troubleshooting small value capacitors.

NOTE: Make reference to Special Instruction, SEHS7734 for more complete information for use of the 6V7070 Multimeter.

Battery

------ WARNING! ------

Never disconnect any charging unit circuit or battery circuit cable from battery when the charging unit is operated. A spark can cause an explosion from the flammable vapor mixture of hydrogen and oxygen that is released from the electrolyte through the battery outlets. Injury to personnel can be the result.

--------WARNING!------

The battery circuit is an electrical load on the charging unit. The load is variable because of the condition of the charge in the battery. Damage to the charging unit can result if the connections (either positive or negative) between the battery and charging unit are broken while the charging unit is in operation. This is because the battery load is lost and there is an increase in charging voltage. High voltage can damage, not only the charging unit, but also the regulator and other electrical components.

Use the 4C4911 Battery Load Tester, the 8T0900 Ammeter Tool Gp and the 6V7070 Multimeter to load test a battery that does not hold a charge when in use. See Special Instruction, SEHS9249 for the correct procedure and specifications to use.

Charging System

The condition of charge in the battery at each regular inspection will show if the charging system operates correctly. An adjustment is necessary when the battery is constantly in a low condition of charge or a large amount of water is needed (more than one ounce of water per cell per week or per every 100 service hours).

When it is possible, make a test of the charging unit and voltage regulator on the engine, and use wiring and components that are a permanent part of the system. Off engine (bench) testing will give a test of the charging unit and voltage regulator operation. This testing will give an indication of needed repair. After repairs are made, again make a test to give proof that the units are repaired to their original condition of operation.

Before the start of on engine testing, the charging system and battery must be check as shown in the Steps that follow:

1. Battery must be at least 75 percent (1.225 Sp Gr) fully charged and held tightly in place. The battery holder must not put too much stress on the battery.

2. Cables between the battery, starting motor and engine ground must be the correct size. Wires and cables must be free of corrosion and have cable support clamps to prevent stress on battery connections (terminals).

3. Leads, junctions, switches, and panel instruments that have direct relation to the charging circuit must give correct circuit control.

4. Inspect the drive components for the charging unit to be sure they are free of grease and oil and have the ability to operate the charging unit.

Alternator Regulator Adjustment

When an alternator is charging the battery too much or not enough, the charging rate of the alternator should be checked. Make reference to the Specifications module to find all testing specifications for the alternators and regulators.

No adjustment can be made to change the rate of charge on the alternator regulators. If rate of charge is not correct, a replacement of the regulator is necessary.

Alternator Pulley Nut Tightening

Tighten the nut that holds the pulley to specifications given in the Specification Module.



Tools To Tighten Alternator Pulley Nut

(1) 8T9293 Torque Wrench.
(2) 8S1588 Adapter (1/2 inch female to 3/8 inch male).
(3) 2P8267 Socket Assembly.
(4) 8H8517 Combination Wrench (1 1/8 inch).
(5) 8T5314 Adapter Socket.

Starting System

Use the multimeter in the DCV range to find starting system components which do not function.

Move the start control switch to activate the starter solenoid. Starter solenoid operation can be heard as the pinion of the starting motor is engaged with the ring gear on the engine flywheel.

If the solenoid for the starting motor will not operate, it is possible that the current from the battery did not get to the solenoid. Fasten one lead of the multimeter to the connection (terminal) for the battery cable on the solenoid. Put the other lead to a good ground. A zero reading is an indication that there is a broken circuit from the battery. More testing is necessary when there is a voltage reading on the multimeter.

The solenoid operation also closes the electric circuit to the motor. Connect one lead of the multimeter to the solenoid connection (terminal) that is fastened to the motor. Put the other lead to a good ground. Activate the starter solenoid and look at the multimeter. A reading of battery voltage shows the problem is in the motor. The motor must be removed for further testing. A zero reading on the multimeter shows that the solenoid contacts do not close. This is an indication of the need for repair to the solenoid or an adjustment to be made to the starter pinion clearance.

Make a test with one multimeter lead fastened to the connection (terminal) for the small wire at the solenoid and the other lead to the ground. Look at the multimeter and activate the starter solenoid. A voltage reading shows that the problem is in the solenoid. A zero reading is an indication that the problem is in the start switch or the wires for the start switch.

Fasten one multimeter lead to the start switch at the connection (terminal) for the wire from the battery. Fasten the other lead to a good ground. A zero reading indicates a broken circuit from the battery. Make a check of the circuit breaker and wiring. If there is a voltage reading, the problem is in the start switch or in the wires for the start switch.

A starting motor that operates too slow can have an overload because of too much friction in the engine being started. Slow operation of the starting motor can also be caused by a short circuit, loose connections and/or dirt in the motor.

Pinion Clearance Adjustment

When the solenoid is installed, make an adjustment of the pinion clearance. The adjustment can be made with the starting motor removed.



Connection For Checking Pinion Clearance

(1) Ground terminal.
(2) SW terminal.
(3) Connector from Motor terminal on solenoid to motor.

1. Install the solenoid without connector (3) from the MOTOR connections (terminal) on solenoid to the motor.

2. Connect a battery, of the same voltage as the solenoid, to the terminal (2), marked SW.

3. Connect the other side of the battery to ground terminal (1).

4. Connect for a moment a wire from the solenoid connection (terminal) marked Motor to the ground connection (terminal). The pinion will shift to crank position and will stay there until the battery is disconnected.



Pinion Clearance Adjustment

(4) Shaft nut.
(5) Pinion.
(6) Pinion clearance.

5. Push the pinion toward the commutator end to remove free movement.

6. Pinion clearance (6) must be 8.3 to 9.9 mm (.33 to .39 in).

7. To adjust pinion clearance, remove plug and turn nut (4).

8. After the adjustment is completed, install the plug over adjustment nut (4) and install connector (3) between the Motor terminal on the solenoid and the starting motor.

Air Starting System

Pressure Regulating Valve



Pressure Regulating Valve (Typical Illustration)

(1) Adjustment screw.
(2) Regulator inlet.
(3) Regulator outlet.

To check and adjust the pressure regulating valve, use the procedure that follows:

1. Drain the line to the pressure regulating valve or drain the air storage tank.

2. Disconnect the regulator from the starter control valve.

3. Connect an 8T0849 Pressure Indicator to regulator outlet (3).

4. Put air pressure in the line or tank.

5. Check the pressure.

6. Adjust the pressure regulating valve to ... 690 to 1030 kPa(100 to 150 psi)

7. Remove the air pressure from the line or tank.

8. Remove the 8M2885 Pressure Indicator and connect the air pressure regulator to the line to the air starting motor.

Each engine application will have to inspected to get the most acceptable starting results. Some of the factors that affect regulating valve pressure setting are: attachment loads pulled by engine during starting, ambient temperature conditions, oil viscosity, capacity of air reservoir, and condition of engine (new or worn).

The advantage of setting the valve at the higher pressure is increased torque for starting motor and faster rotation of engine. The advantage of setting the valve at the lower pressures is longer time of engine rotation for a given capacity of supply air.

Lubrication

Always use an air line lubricator with these air starting motors.

For temperatures above 0°C (32°F), use a non detergent 10W engine oil.

For temperatures below 0°C (32°F), use air tool oil.

Air Starting Motor



Components Of The Air Starting Motor

(1) Motor housing cover.
(2) Plug.
(3) Plug.
(3A) Plug.
(6) Bolt (cap screw).
(7) Lockwasher.
(8) Gasket.
(9) Rotor rear bearing.
(10) Bearing retainer.
(11) Rear end plate.
(12) Cylinder.
(13) Dowel.
(14) Rotor vane.
(15) Rotor.
(16) Front end plate.
(17) Rotor front bearing.
(18) Motor housing.
(19) Gear case gasket.
(20) Rotor pinion.
(21) Rotor pinion retainer.
(22) Gear case.
(23) Bearing rejecting washer.
(24) Rear bearing (for the drive shaft.)
(25) Drive gear.
(25A) Thrust washer.
(26) Key (for the drive gear).
(27) Front bearing (for the drive shaft).
(28) Gear case cover.
(29) Grease seal (for the drive shaft).
(30) Cover seal.
(31) Piston seal.
(32) Bolt.
(33) Lockwasher.
(34) Drive shaft.
(35) Drive shaft collar.
(36) Piston.
(36A) Piston ring.
(37) Shift ring.
(38) Shift ring retainer.
(39) Shift ring spacer.
(40) Piston return spring.
(41) Return spring seat.
(42) Starter drive (pinion).
(43) Lockwasher.
(44) Bushing (for the bolts).
(45) Drive housing.
(46) Drive housing bushing.
(47) Oiler felt (for the bushing).
(48) Oiler plug.



Rear View Of The Cylinder And Rotor For Clockwise Rotation

(12) Cylinder.
(12A) Air inlet passages.
(12B) Dowel hole.
(15) Rotor.



Air Starting Motor

(6) Bolt.
(12) Cylinder.
(15) Rotor.
(16) Front end plate.
(22) Gear case.
(25) Drive gear.
(28) Gear case cover.
(29) Grease seal.
(32) Bolt.
(34) Drive shaft.
(35) Drive shaft collar.
(42) Starter drive (pinion).
(45) Drive housing.
(49) Air inlet.
(50) Deflector (air outlet).
(51) Mounting flange (on the drive housing).

Cylinder (12) must be assembled over rotor (15) and on front end plate (16) so dowel hole (12B) and inlet passages (12A) for the air are as shown in the rear view illustration of the cylinder and rotor. If the installation is not correct, starter drive (42) will turn in the wrong direction.

Tighten the bolts (6) of the rear cover in small increases of torque for all bolts until all bolts are tight 30 ± 5 N·m (22 ± 4 lb ft).

Put a thin layer of lubricant on the lip of seal (29) and on the outside of drive shaft collar (35), for installation of drive shaft (34). After installation of the shaft through gear case cover (28) check the lip of grease seal (29). It must be turned correctly toward drive gear (25). If the shaft turned the seal lip in the wrong direction, remove the shaft and install again. Use a tool with a thin point to turn the seal lip in the correct direction.

Tighten bolts (32) of the drive housing in small increases of torque for all bolts until all bolts are tight 11.3 N·m (100 lb in).

Check the motor for correct operation. Connect an air hose to motor air inlet (49) and make the motor turn slowly. Look at starter drive (42) from the front of drive housing (45). The pinion must turn clockwise.

Connect an air hose to the small hole with threads in drive housing (45), nearer gear case (22). When a little air pressure goes to the drive housing, starter drive (42) must move forward to the engaged position. Also, the air must get out the other hole with threads nearer mounting flange (51).



Components Of The Air Starting Motor

(1) Motor housing cover.
(2) Plug.
(3) Nameplate.
(4) Screw.
(5) Bolt (cap screw).
(6) Plug.
(7) Rear end plate.
(8) O-ring seal.
(9) Cylinder housing kit.
(10) Dowel.
(11) Front end plate.
(12) O-ring seal.
(13) Rotor.
(14) Rear rotor bearing.
(15) O-ring seal.
(16) Retaining nut.
(17) Retaining nut cover.
(18) Front rotor bearing.
(19) Wave washers.
(20) Rotor vanes.
(21) Rotor pinion.
(22) Bolts.
(23) Gear case.
(24) O-ring seal.
(25) Drive gear.
(26) Drive gear bearing.
(27) Retaining ring.
(28) Gear case seal.
(29) Retaining ring.
(31) Piston kit.
(32) O-ring seal.
(33) Piston bearing.
(34) Retaining ring.
(35) Clutch jaw kit.
(36) Retaining ring.
(37) Clutch springs.
(38) Clutch spring cup.
(39) Piston return springs.
(40) Return spring seat.
(41) Drive shaft.
(42) Drive shaft spacer.
(43) Drive shaft washer.
(44) Bolt.
(45) Drive shaft collar.
(46) Drive pinion.
(47) Bolt.
(48) Drive housing kit.
(49) Drive housing seal.
(50) Drive housing bearing.
(51) O-ring seal.
(52) Drive housing washer.
(53) Drive housing gasket.
(54) Bolts.



Air Starting Motor

(5) Bolts.
(7) Rear end plate.
(16) Retaining nut.
(22) Bolts.
(28) Gear case seal.
(44) Bolt.
(47) Bolt.
(54) Bolts.

During assembly put two pieces of 0.10 mm (.004 in) shim stock between rotor body and rear end plate (7). Tighten retaining nut (16) until there is slight drag on the shim stock. Tighten the clamping screw in the retaining nut (16). The clearance between the rotor assembly and the end plate can be 0.05 to 0.13 mm (.002 to .005 in).

Install four bolts (5), and tighten to a torque of ... 27 N·m(20 lb ft).

Tighten bolts (22) to a torque of ... 68 N·m (50 lb ft).

Install gear case seal (28) lip side first, into the small bore of the gear case. Put a thin layer of lubricant on the lip type seal and all O-ring seals.

Install bolt (44) and tighten to a torque of ... 75 N·m(55 lb ft).

Install four bolts (54). Tighten to a torque of ... 27 N·m(20 lb ft).

Tighten the bolt (47) to a torque of ... 75 N·m(55 lb ft).

After assembly, turn the drive pinion by hand in the direction of starter rotation. The clutch should ratchet smoothly with a slight "clicking" action. Attach a hose to the "IN" port and apply 345 kPa (50 psi) air pressure. The drive pinion should move outward and air will escape from the "OUT" port. Plug the "OUT" port and apply 1034 kPa (150 psi) air pressure.

The distance measured from the face of the drive pinion to the face of the mounting flange should be 70.5 mm (2.77 in). Remove pressure from the "IN" port. The measured distance should be 46.3 mm (1.82 in).

Connect a 9 mm (3/8 in) inlet hose at 620 kPa (90 psi). The starter should run smoothly. Plug the exhaust port and apply 207 kPa (30 psi) air pressure. Immense starter in a non-flammable solvent for 30 seconds. If the starter is properly sealed, no air bubbles will appear.

Instruments And Indicators

Magnetic Pickup


Typical Illustration

(1) Clearance between magnetic pickup and flywheel ring gear ... 0.56 to 0.84 mm(0.022 to .033 in)

NOTE: This distance is set by turning magnetic pickup into threads until magnet is against the gear tooth while the engine is stopped. Now back magnetic pickup out 1/2 turn ± 30 degrees and tighten nut (2) as follows.

(2) Nut. Tighten nut to a torque of ... 45 ± 7 N·m(33 ± 5 lb ft)

Oil Pressure Sending Unit



Sending Unit For Oil Pressure

(1) Terminal.
(2) Fitting.

1. Connect the sending unit to a pressure source that can be measured with accuracy.

2. Connect an ohmmeter between fitting (2) and terminal (1).

3. Take resistance readings at the pressures shown in the chart.

4. If a unit does not have the correct resistance readings, make a replacement of the unit.

Water Temperature Sending Unit



Sending Unit For Water Temperature

(1) Terminal.
(2) Nut.
(3) Bulb.

1. Connect an ohmmeter between terminal (1) and nut (2). Put bulb (3) in a pan of water. Do not let the bulb have contact with the pan.

2. Put a thermometer in the water to measure the temperature.

3. Take a resistance reading at the temperatures shown in the chart.

4. If a unit does not have the correct resistance readings, make a replacement of the unit.

Electric Indicators

1. Put the indicator in position with the letters horizontal and the face 30 degrees back from vertical.



Writing Diagram For Test

(1) Terminal (for test voltage).
(2) Test resistance.

2. Connect the indicator in series with the power source and the middle test resistance shown in the chart.

3. Let the indicator heat at the middle resistance for five minutes, then give the pointer position for all of the resistance given.

Mechanical Indicators For Temperature


Direct Reading Indicator

To check these indicators, put the bulb of the indicator in a pan of oil. Do not let the bulb touch the pan. Put a thermometer in the oil to measure the temperature. Make a comparison of temperatures on the thermometer with the temperatures on the direct reading indicator.

Mechanical Indicators For Pressure


Direct Reading Indicator

To check these indicators connect the indicator to a pressure source that can be measured with accuracy. Make a comparison of pressure on the indicator of test equipment with the pressures on the direct reading indicator.

Shutoff Solenoids



Rack Solenoid

(1) Travel.
(2) Distance between shaft and plate.
(3) Start position of plunger plate from mounting flange.

5N8293

2W6665

NOTE: Refer to Specifications, 3408C & 3412C Marine Engines, SENR1131 for the proper dimensions shown.

Two checks must be made on the engine to give proof that the solenoid adjustment is correct.

1. The adjustment must give the plunger enough travel to move the rack to the fuel shutoff position. Use the 6V9128 Rack Position Tool Group to make sure the rack goes to the fuel shutoff position.

2. The adjustment must give the plunger enough travel to cause only the "hold-in" windings of the solenoid to be activated when the rack is held in the fuel shutoff position. Use a thirty ampere ammeter to make sure the plunger is in the "hold-in" position. Current needed must be less than two amperes.



Rack Solenoid

(1) Solenoid plunger.
(2) Stop bolt.
(3) Locknut.
(4) Lock wire and seal.

7W7787

1. Remove any manual shutoff shaft linkage from the governor.

2. Remove lock wire and seal (4). Loosen locknut (3) and turn stop bolt (2) several turns out [away from solenoid plunger (1)].

3. Rotate the manual shutoff shaft clockwise to the shutoff position. Fasten the shaft in the shutoff position.

4. Hold locknut (3) and turn stop bolt (2) in until the bolt contacts shutoff solenoid plunger (1).

5. Turn stop bolt (2) in an additional 3/4 ±1/4 turn and tighten locknut (3).

6. Release the manual shutoff shaft.

7. Start the engine.

8. The engine should run at low idle without a problem.

9. To test the solenoid stop bolt adjustment, run the engine at high idle and no load. Shut off the engine and the engine should stop.

10. If the engine continues to run at reduced speed or shuts down too slowly, turn the stop bolt (2) out an additional 1/4 turn and repeat Step 9.

11. If possible, apply a load to the engine and make sure the engine will maintain the normal full load speed. Remove the load and return the engine to low idle.

12. Shut off the engine.

13. Install a new lock wire and seal (4).

Caterpillar Information System:

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