Introduction

NOTE: For Specifications with illustrations, make reference to ENGINE SPECIFICATIONS FOR D342 INDUSTRIAL & MARINE ENGINES, Form No. REG01362. If the Specifications in Form No. REG01362 are not the same as in the Systems Operation and the Testing and Adjusting, look at the printing date on the back cover of each book. Use the Specifications given in the book with the latest date.

Troubleshooting

Troubleshooting can be difficult. On the following pages there is a list of possible problems. To make a repair to a problem, make reference to the cause and correction.

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 can not give all possible problems and corrections. The serviceman must find the problem and its source, then make the necessary repairs.

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

2. Engine Will Not Start.

3. Misfiring or Running 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. Loud Noise (Clicking) From Valve Compartment.

10. Oil In Cooling System.

11. Mechanical Noise (Knock) In Engine.

12. Fuel Consumption Too High.

13. Loud Noise From Valves or Valve Drive Components.

14. Little Movement of Rocker Arm and Too Much Valve Clearance.

15. Valve Rotocoil or Spring Lock is Free.

16. Oil at the Exhaust.

17. Little or No Valve Clearance.

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. Starting Motor Does Not Turn.

26. Alternator Gives No Charge.

27. Alternator Charge Rate Is Low or Not Regular.

28. Alternator Charge Too High.

29. Alternator Has Noise.

30. Exhaust Temperature Too High.

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. Finding the source of the problem is difficult, especially when smoke is coming from the exhaust. Smoke coming from the exhaust can be caused by a bad fuel injection valve, but it can also be caused by the following:

a. Not enough air for good combustion.

b. An overload at high altitude.

c. Burning of too much oil.

d. Not enough compression.

Fuel System Inspection

1. Look at the reading on the gauge for fuel pressure. Not enough fuel pressure is an indication of a problem with the components that send fuel to the engine.

2. 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.

3. Check the fuel lines for fuel leakage. Be sure the fuel supply line does not have a restriction or a bad bend.

4. Install a new fuel filter. Clean the primary fuel filter if the machine is so equipped.

5. Remove any air that may be in the fuel system.

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

Testing Fuel Injection Equipment

An easy check can be made to find the cylinder that is misfiring, or running rough, and causing black smoke to come out of the exhaust pipe.

Run the engine at the speed that gives misfiring. Loosen the fuel line nut at a fuel injection pump or valve. 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 running. 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 running, test the injection pump and injection valve for that cylinder.

Checking the Fuel Injection Valves

Check the fuel injection valves for:

1. Too much carbon on the tip of the nozzle or in the nozzle orifice.

2. Wear of the orifice.

3. Nozzle screen being dirty.

Use the Caterpillar Diesel Fuel Injection Test Bench to test the nozzle.

Checking the Pump Plunger and Lifter Yoke

Check timing dimension for the fuel injection pumps. Make an adjustment if necessary, with the pump housing on the engine. When an adjustment to the timing dimensions 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.

When there is too much wear on the pump plunger, the lifter yoke 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 lifter yokes in the place of those with wear.

WEAR BETWEEN LIFTER YOKE AND PLUNGER
Fig. A illustrates the contact surfaces of a new pump plunger and a new lifter yoke. In Fig. B the pump plunger and lifter yoke have worn considerably. Fig. C shows how the flat end of a new plunger does not make a good contact with a worn lifter yoke. The result is rapid wear to both parts.

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.

Precombustion Chamber

5F8353 Wrench.

Use the 5F8353 Wrench to remove or install the precombustion chambers. Put 9M3710 Anti-Seize Compound on the threads before installation. Tighten the precombustion chamber to 200 lb.ft. (27.7 mkg).

To remove a precombustion chamber use the following procedure:

1. Remove the fuel line. Put a cap, to keep out dirt, on the fuel injection valve.

2. Remove valve cover (1), nuts and washers (3 and 4), and fuel injection valve (2).

PREPARATION FOR PRECOMBUSTION CHAMBER REMOVAL
1. Valve cover. 2. Fuel injection valve. 3. Nut and washer. 4. Nut and washer.

5F8353 WRENCH INSTALLED
5. 5F8353 Wrench.

3. Put 5F8353 Wrench (5) in the precombustion chamber and remove the precombustion chamber.

REMOVING PRECOMBUSTION CHAMBER

Position for Precombustion Chambers (With glow plugs)

DIAGRAM OF POSITION FOR PRECOMBUSTION CHAMBER
1. Center line of the precombustion chamber that is at a right angle to the center line of the crankshaft. 2. Center line of the precombustion chamber that is parallel to the center line of the crankshaft. 3. Center line of the crankshaft.

Put 1P6442 Gasket, with "4D" on it, on the precombustion chamber. Put 9M3710 Anti-Seize Compound on the threads of the precombustion chamber. Install the precombustion chamber in the cylinder head and tighten to 200 lb.ft. (27.7 mkg). If the opening for the glow plug is not in the "A range", remove the precombustion chamber and 1P6442 Gasket. If the opening for the glow plug was in the "B range" use 1P6441 Gasket with "4J" on it. If the opening for the glow plug was in the "C range" use 5H2579 Gasket with "4C" on it. Put 9M3710 Anti-Seize Compound on the threads of the precombustion chamber. Install the precombustion chamber with the correct gasket and tighten the precombustion chamber to 200 lb.ft. (27.7 mkg).

Fuel Injection Service

Injection Valve

Check the seat of the nozzle and the seat in the precombustion chamber before installing the fuel injection valve. It is important to keep the correct torque on the nut that holds the fuel nozzle in the precombustion chamber. Tighten the nut to 105 ± 5 lb.ft. (14.5 ± 0.7 mkg). There will be damage to the nozzle if the nut is too tight. If the nut is not tight enough the nozzle can leak.

Remove of Fuel Injection Pump

When injection pump barrels and plungers are removed from the injection pump housing, keep the parts of each pump together so they can be installed back in their original location.

Be careful when removing injection pumps. 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 putting the plunger in the bore of the barrel.

1. Remove the fuel injection line from the pump and install cover (1) and plug (3).

REMOVING FUEL INJECTION PUMP
1. Cover. 2. Plug. 3. Plug. 4. Seal.

2. Remove the bolts and clamps holding the fuel injection pump to the housing and lift the pump straight up to clear the dowel pins and the pump plunger. Install seals (4) and plug (2) for protection from dirt.

3. Slide the end of the plunger out of the yoke in the lifter and remove the plunger. Be sure the plunger is installed in the barrel from which it was removed.

Installation of Injection Pump

The seal under the machined surface, around the large diameter of the pump, must be in correct position when the pump is installed. Also, there must be a seal around the fuel outlet ferrule on the fuel pump housing. If either seal has damage install a new seal.

1. Remove the pump plunger from the barrel.

2. Wash the pump plunger and barrel with clean diesel fuel before installing.

3. Turn the pump plunger, until tooth (6) with a mark is in alignment with mark (5) on the rack.

INSTALLING FUEL INJECTION PUMP
5. Mark on rack. 6. Tooth mark.

4. Put the end of the plunger into the yoke in the lifter.

5. Lower the pump barrel onto the plunger, taking care that the pump plunger is straight in the barrel.

6. Lower the pump onto the dowel pins and fasten in place. Tighten bolts (8) first and then tighten bolts (7). Torque for bolts (7) and (8) is 32 ± 5 lb.ft. (4.4 ± 0.7 mkg).

SEQUENCE TO TIGHTEN BOLTS
7. Bolts, tighten second. 8. Bolts, tighten first.

7. Use 5P144 Fuel Line Socket (9) and tighten the nuts holding the fuel lines to 30 ± 5 lb.ft. (4.1 ± 0.7 mkg).

TIGHTENING NUTS FOR FUEL LINES
9. 5P144 Fuel Line Socket.

Finding Top Center Compression Position For No. 1 Piston

2P8300 Engine Turning Tool Group.

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

1. Remove valve cover (1) at the front of the engine.

LOCATION OF VALVE COVER
1. Valve cover.

2. Remove cover (2) from the top of the housing for the flywheel.

TIMING MARK COVER
2. Cover.

3. Turn the flywheel in the direction of engine rotation until No. 1 piston is at top center (TC) on the compression stroke. An indication is by pointer (3).

TIMING MARKS ON FLYWHEEL
3. Pointer.

4. Look at the valves for No. 1 cylinder (the two valves at the front of the engine). The intake valve and exhaust valve for No. 1 cylinder must be closed.

5. If the intake and exhaust valves for No. 1 cylinder are not closed, turn the flywheel in the direction of engine rotation 360°. If both valves are now closed, this is top center (TC) compression position for No. 1 piston.

NOTE: If the flywheel is turned too far, turn it in the other direction a minimum of 60°, then turn the flywheel in the direction of engine rotation until No. 1 piston is at top center (TC) on compression stroke.

ENGINE TURNING TOOLS
4. 2P8294 Housing. 5. 2P8299 Pinion.

Checking The Timing Of The Fuel Injection Pumps

Checking with 1P540 Flow Checking Tool Group

1P540 Flow Checking Tool Group.3S2954 Timing Indicator Group.9M9268 Dial Indicator.2P8294 Housing.2P8299 Pinion.

See Special Instruction (FM035709) for complete instructions for the fuel flow method of engine timing (injection sequence).

MEASURING PISTON TRAVEL
1. 3S3263 Adapter. 2. 9M9268 Dial Indicator. 3. 3S3264 Rod. 4. Precombustion chamber. 5. Inlet port. 6. Piston. 7. Crankshaft.

Travel of piston (6), from point of closing inlet port (5) at top center (TC) can be found by using the 3S2954 Timing Indicator Group. Change the travel of piston (6) into degrees to see if engine timing (injection sequence) is correct.

The 1P540 Flow Checking Tool Group is used to put pressure in the fuel system. Use the 1P539 Tank Assembly to get 10 to 15 psi (0.70 to 1.05 kg/cm²) fuel pressure.

See the chart to find angle relation to indicator reading. At the indicator reading and timing angle for this engine, fuel flow from the injection pump should be 5 to 12 drops per minute point of closing inlet port (5).

NOTE: If the timing of the fuel system is different than the correct timing dimension in the chart, make reference to FUEL PUMP LIFTER SETTING (ON ENGINE).

Fuel Pump Lifter Setting (On Engine)

2P8300 Engine Turning Tool Group.6F6922 Micrometer Depth Gauge.9M4567 Lifter Adjustment Wrench.9M4568 Lifter Adjustment Wrench.

If the lifters for the fuel injection pumps have been removed or if the original setting has been changed, it will be necessary to make an adjustment to the setting for the lifters.

Check the setting of the lifters for the fuel injection pumps. Make an adjustment to the setting, if necessary, for the compensation of wear to the timing gears, lifters, or the plungers for the fuel injection pumps.

The adjustment for the lifters for the fuel injection pumps can be made in the following way:

1. Turn the flywheel in the direction of engine rotation to top center (TC) on the compression stroke of the cylinder for the lifter to have the adjustment.

PUTTING TIMING POINTER AT (TC) MARK

NOTE: If the flywheel is turned too far, turn it in the other direction a minimum of 60° and again turn the flywheel in the direction of engine rotation until the timing pointer is in alignment with the (TC) mark on the flywheel.

2. Check the distance (A) with the 6F6922 Micrometer Depth Gauge and make an adjustment to the setting for the lifter if necessary. Use the 9M4567 and 9M4568 Lifter Adjustment Wrenches for the adjustment of the lifters.

MEASURING LIFTER SETTING
A. 1.8088 ± .0005 in. (45.944 ± 0.013 mm) distance of lifter setting.

LIFTER SETTING TOOLS
1. 9M4568 Lifter Adjustment Wrench. 2. 9M4567 Lifter Adjustment Wrench.

3. If all the lifters are to have an adjustment, do all in the firing order (injection sequence) of the engine. The firing order (injection sequence) is 1, 5, 3, 6, 2, 4.

NOTE: It is important when checking and making adjustments to the lifters that the engine flywheel be turned in the direction of engine rotation. After a lifter has been checked or an adjustment has been made, turn the flywheel approximately 20° in the direction of engine rotation. Again measure distance (A). If this distance is less than measurement when checked with the flywheel at (TC), it is an indication that the lifter is going up and was checked at the correct position.

Fuel Pump Lifter Setting (Off Engine)

1P5600 Lifter Setting Tool Group.6F6922 Micrometer Depth Gauge.

The checking and making adjustment to the setting for the lifters off the engine will result in the correct timing of the injection of fuel if the housing is installed on a new engine or on an engine which has new timing gears. This method does not make compensation for wear in the timing gears of an engine that has had many hours of operation.

To be sure of the correct timing for the injection of fuel, it is important to check the setting of the lifters with the housing for the fuel injection pumps installed on the engine. To check or make an adjustment of the lifters with the housing on the engine, make reference to FUEL PUMP LIFTER SETTING (ON ENGINE).

Use the following procedure for checking or making an adjustment to the setting for the lifters with the pump housing off the engine.

1P5600 TOOL GROUP
The tools in the list are the tools needed from the 1P5600 Tool Group to check or make lifter setting OFF ENGINE. 1. 1P7410 Timing Plate. 2. 7F8751 Shaft. 3. 4B7618 Wrench. 4. 4B7617 Wrench. 5. S1594 Bolt. 6. S509 Bolt. 7. 1P7415 Pointer. 8. 9M4567 Lifter Adjustment Wrench. 9. 9M4568 Lifter Adjustment Wrench. 10. 2S6160 Washer.

1. Put timing plate (1) on the drive end of the camshaft using shaft (2), bolt (6), and washer (10). Put the extended part of shaft (2) into the groove in the end of the camshaft, this will position the timing plate in relation to the camshaft and permit rotation of the camshaft by the timing plate.

2. Put pointer (7) on the dowel at the top of the housing and hold in position with bolt (5).

MICROMETER DEPTH GAUGE
11. 6F6922 Micrometer Depth Gauge.

FUEL PUMP LIFTER SETTING (OFF ENGINE)
1. 1P7410 Timing Plate. 5. S1594 Bolt. 6. S509 Bolt. 7. 1P7415 Pointer. 10. 2S6160 Washer. 11. 6F6922 Micrometer Depth Gauge. 12. Edge of pointer. A. 1.8815 ± .0010 in. (47.790 ± 0.025 mm) distance of lifter setting.

3. Find in the chart the degree for the timing plate for the lifter to be checked or have an adjustment. Put the timing plate to this degree by turning it clockwise until the correct degree is in alignment with the edge (12) of the pointer.

4. Check the distance (A) with depth gauge (11) and make an adjustment to the setting for the lifter if necessary. Use the 9M4567 and 9M4568 Lifter adjustment Wrenches for the adjustment of the lifters.

NOTE: The distance (A) is the distance from the flat surface on the top of the housing to the surface in the yoke where the plunger of the pump contacts. To get a correct measurement, be sure the flat surface on the top of the housing is clean, dry, and free of paint.

5. If all lifters are to be checked or have an adjustment, use the same procedure in the firing order (injection sequence) of the engine. The firing order (injection sequence) is 1, 5, 3, 6, 2, 4. Check the setting of each lifter after the adjustment has been made and the locknut tightened to make sure the setting has not changed.

Governor Adjustments

High and Low Idle RPM

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NOTICE
A mechanic with training in governor adjustments is the only one to make the adjustment to the high idle and low idle rpm. The correct high idle and low idle rpm, and the measurement for adjustment of the fuel rack are in the book RACK SETTING INFORMATION.

The engine idle rpm can be checked at the connection for the tachometer drive on the service meter after the cover has been removed. The rpm will be one half of engine rpm.

CHECKING ENGINE RPM

To make an adjustment to the high and low idle rpm use the following procedure:

1. Remove cover (3) from the top of the housing for the governor.

2. Turn adjustment screw (4) as necessary to change high idle rpm. Turn adjustment screw (2) as necessary to change low idle rpm.

LOCATION OF ADJUSTMENTS
1. Retainer holes in cover. 2. Adjustment screw for low idle. 3. Cover. 4. Adjustment screw for high idle.

3. After an idle adjustment is made, move the governor lever to change the rpm of the engine.

4. Now move the governor lever back to the point of first adjustment. Use this procedure until the idle rpm is the same as the idle rpm given in the book RACK SETTING INFORMATION.

NOTE: Turning the adjustment screws counterclockwise will cause the rpm to increase. Turning the adjustment screws clockwise will cause the rpm to decrease.

5. When governor adjustment is correct, put the cover on the governor. Then put the cover on the service meter.

Fuel Rack Setting

9S7343 Bracket Assembly.9S7344 Clamp Assembly.8S2283 Dial Indicator.3S3269 Contact Point.

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NOTICE
Fuel rack setting is done carefully at the factory. Do not change the fuel rack setting unless it is known to be wrong. A wrong setting of the fuel rack can cause a problem with the turbocharger. Make reference to the book RACK SETTING INFORMATION for the correct rack setting.

To check or make an adjustment to the fuel rack setting, use the following procedure:

1. Remove governor seal (6), cover (5), and the gasket. Remove cover (7) and the gasket.

TOOLS FOR SETTING FUEL RACK
1. 9S7343 Bracket Assembly. 2. 9S7344 Clamp Assembly. 3. 3S3269 Contact Point. 4. 8S2283 Dial Indicator.

COVERS TO BE REMOVED
5. Rear cover. 6. Governor seal. 7. Side cover.

2. Put bracket assembly (1) on the housing. Position clamp assembly (2) on fuel rack (8) .19 in. (4.8 mm) from the third mark on the fuel rack from the governor end of the housing (Distance A). Tighten the bolt in the clamp assembly to hold the clamp assembly in this position.

BRACKET AND CLAMP INSTALLED
1. 9S7343 Bracket assembly. 2. 9S7344 Clamp Assembly. 8. Fuel rack. A. .19 in. (4.8 mm) distance from third mark on rack to clamp assembly.

3. Disconnect the linkage that controls the governor on the outside of the governor.

4. Put contact point (3) on dial indicator (4). Move the fuel rack to the fuel closed position. Install the indicator and make an adjustment to the indicator to read minus .461 in. To make this adjustment:

a. Move the indicator until the revolution counter (9) is between the red 3 and 4.

b. Turn the dial of the indicator until pointer (10) is on zero.

c. Move the indicator .061 in. more (in the red) for the minus .461 in. reading.

d. Tighten the bolt in the bracket assembly to hold the indicator at this reading.

DIAL INDICATOR AT MINUS .461 IN.
9. Revolution counter. 10. Pointer.

TOOLS IN PLACE FOR RACK SETTING
1. 9S7343 Bracket Assembly. 2. 9S7344 Clamp Assembly. 3. 3S3269 Contact Point. 4. 8S2283 Dial Indicator.

5. Move the control lever for the governor toward the fuel opened position until stop collar (11) on fuel rack (8) is against rack stop (12) or torque spring (15). If the engine has a torque spring (15), move the control lever slowly until the stop collar is against but does not move the torque spring. Read the rack setting directly from the indicator.

RACK STOP
8. Fuel rack. 11. Stop collar. 12. Rack stop. 13. Shims. 14. Clamp.

TORQUE SPRING
8. Fuel rack. 11. Stop collar. 12. Rack stop. 13. Shims. 14. Clamp. 15. Torque spring. 16. Spacer.

6. To make an adjustment to the rack setting:

a. To make an increase to the rack setting, remove shims (13) as necessary.

b. To make a decrease to the rack setting, add shims (13) as necessary.

TORQUE SPRING
8. Fuel rack. 11. Stop collar. 12. Rack stop. 13. Shims. 14. Clamp. 15. Torque spring. 17. Spacers.

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 of the air inlet or exhaust system.

Air flow through the air cleaner must not have a restriction of more than 30 in. (762 mm) of water difference in pressure.

Back pressure from the exhaust (pressure difference measurement between exhaust outlet elbow and atmosphere) must not be more than 34 in. (864 mm) for naturally aspirated and 27 in. (686 mm) for turbocharged engines.

Measurement Of Pressure In Inlet Manifold

By checking the pressure in the inlet manifold the efficiency of an engine can be checked by making a comparison with the information given in the book, RACK SETTING INFORMATION. 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 book, RACK SETTING INFORMATION. Development of this information is done with these conditions: 29.4 in. (746.8 mm) of mercury barometric pressure, 85° F (29.4° C) outside air temperature and 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 inlet manifold pressure measurement, than given in the book, RACK SETTING INFORMATION. Outside air that has a lower temperature and higher barometric pressure will cause a higher horsepower and 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 book, RACK SETTING INFORMATION. If the fuel is rated below 35 API, the pressure in the inlet manifold can be more than given in the book, RACK SETTING INFORMATION. BE SURE THAT THE AIR INLET AND EXHAUST DO NOT HAVE A RESTRICTION WHEN MAKING A CHECK OF PRESSURE IN THE INLET MANIFOLD.

Use the 4S6553 Instrument Group to check engine rpm and the pressure in the inlet manifold. This instrument group has a tachometer for reading engine rpm. It also has a gauge for reading pressure in the inlet manifold. Special Instruction (FE036044) is with the tool group and gives instructions for the test procedure.

4S6553 INSTRUMENT GROUP
1. 4S6992 Differential Pressure gauges. 2. Zero adjustment screw. 3. Lid. 4. 8M2743 Gauge. 5. Pressure tap fitting. 6. 4S6991 Tachometer. 7. 4S6997 Manifold Pressure Gauge.

Use the 1P3060 Pyrometer Group to check exhaust temperature. Special Instruction (GMG00697) is with the tool group and gives instructions for the test procedure.

1P3060 PYROMETER GROUP

Crankcase (Crankshaft Compartment) Pressure

Broken or damaged pistons or piston rings can be the cause of too much pressure in the crankcase. This condition will cause the engine to run rough. There will also be more than the normal amount of fumes coming from the crankcase breather. This crankcase pressure can also cause the element for the crankcase breather to have a restriction in a very short time. It can also be the cause of oil leakage at gaskets and seals.

Compression Check

2P8300 Engine Turning Tool Group.

An engine that runs rough can have a leak at the valves, or valves that need adjustment. Run the engine at the speed that gives rough running. To find a cylinder that has low compression or does not have good fuel ignition, loosen a fuel line nut at a fuel injection pump or valve. 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 running. Be sure to tighten each fuel line nut after each cylinder test before the next fuel line nut is loosened. This test can also be an indication that the fuel injection is wrong, so more checking of the cylinder will be needed.

Condition of the valves, valve seats, pistons, piston rings and cylinder liners can be tested by putting air pressure in the cylinder. Special Instruction (GMG00694) gives instructions for the test procedure. It also gives the list of parts needed from Parts Department to make the test. 2P8300 Engine Turning Tool Group is needed for turning the engine.

This test is a fast method of finding the cause of compression loss in a cylinder. Removal of the head and inspection of the valves and valve seats is still necessary to find those small defects that do not normally cause a problem. Repair of these problems is normally done when reconditioning the engine.

Valves

Use the 5S1330 Valve Spring Compressor Assembly with the 5S1329 Jaw to put the valve spring under compression. Use the 5S1322 Valve Keeper Installer with the compressor assembly to make the installation of the valve keepers easier and faster.

The valves can also be removed with 7F4292 Valve Spring Compressor Group. The 7F4290 Adapter is installed on a rocker arm stud. When installing the valve springs with 7F4292 Group, use the FT195 Fabricated Tool to hold the valves in place.

Valve Seat Inserts

Valve seat inserts are available with a larger outside diameter than the original size. The available inserts are in the chart.

Valve Clearance Setting

Refer to LUBRICATION AND MAINTENANCE PROCEDURES for details of valve clearance adjustment.

Valve Guides

The intake and exhaust valves operate in replacement type valve guides. After the valves have been removed, clean the valve stems and valve guides.

The 4H446 Driver is used for installation of new valve guides.

A reamer is used in the bore of each valve guide after installation of the guide. The intake guides are to have a bore size of .4995 ± .0010 in. (12.687 ± 0.025 mm). The exhaust guides are to have a bore size of .5010 ± .0010 in. (12.725 ± 0.025 mm).

Water Directors

There are twelve water directors (1) installed in each cylinder head. They give the coolant the desired direction of flow. On the exhaust side, the coolant flow goes toward the precombustion chambers and the exhaust valve ports; and on the intake side, the coolant flow goes to the other side of the valve ports.

WATER DIRECTORS
1. Water director. 2. Seal. 3. Ferrule.

Water directors are installed with a press in the heads after the alignment of the notch on the director with the V-mark on the head.

Replacement type seals (2) and ferrule (3) go between the head and top of the block. Put soap on the inner surface of the seal and put the seal over the flange on the ferrule before installing. Use the FT117 Seal and Ferrule Assembly Tool to install the seal on the ferrule.

FT117 SEAL AND FERRULE ASSEMBLY TOOL

4. 5H3182 Pin.

5. 2A3672 Spring.

6. Flat Washer.

7. Chain.

8. Upper Rod.

9. Connecting Pin.

10. Bracket.

11. Connecting Joint.

12. Lower Rod.

13. Base.

A. Rubber Seals.

B. Ferrule.

Lubrication System

One of the problems in the following list 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

TURBOCHARGER LUBRICATION VALVE

Too Much Oil Consumption

Oil Leakage on Outside of Engine

Check for leakage at 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 is coming 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 cylinders can be the cause of blue smoke. There are three 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 not installed correctly.

Too much oil consumption can also be the result of using oil with the wrong viscosity. Oil with a thin (low) viscosity can be caused from dirt or fuel getting in the crankcase, or by the engine getting too hot.

Oil Pressure Is Low

An oil pressure gauge that has a defect may give an indication of low oil pressure.

When the engine is running at full load rpm with SAE 10 oil, temperature at 195 ± 10°F (90 ± 6°C), the oil pressure measured at the clean side of the oil filter at the oil filter base will be 39 ± 7 psi (2.74 ± 0.49 kg/cm²).

A lower pressure reading, 25 ± 7 psi (1.62 ± 0.49 kg/cm²), is normal at low idling speeds. An 8M2744 Gauge, which is part of 7S8875 Hydraulic Test Box, can be used for checking pressure in the system.

7S8875 HYDRAULIC TEST BOX

Crankcase Oil Level

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

Oil Pump Does Not Work Correctly

The inlet screen of the supply tube for the oil pump can have a restriction. This will result in cavitation and a loss of oil pressure. Air leakage in the supply side of the oil pump will also cause cavitation and loss of oil pressure. If the pressure regulating valve for the system is held in the open (unseated) position, the lubrication system can not get to maximum pressure. Oil pump gears that have too much wear will cause a reduction in oil pressure.

Oil Filter and Oil Cooler Bypass Valves

If the bypass valve for the oil filter is held in the open position (unseated) and the oil filter has a restriction, a reduction in oil pressure can result.

The bypass valve is in the oil filter base. The bypass valve will cause the flow of oil to go around the filter elements when there is a reduction to the flow through the elements.

If the oil cooler has a restriction, the oil cooler bypass valve in the oil filter base will open. This will cause the flow of oil to go around the oil cooler.

Too Much Clearance at Engine Bearings or Open, Broken or Disconnected Oil Line or Passage in Lubrication System

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.

Oil Cooler

Look for a restriction in the oil passages of the oil cooler.

If the oil cooler has a restriction the oil temperature will be higher than normal when the engine is running. The oil pressure of the engine will become low if the oil cooler has a restriction.

Oil Pressure Is High

Oil pressure will be high if the bypass valve for the 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 gauge for oil pressure shows the correct oil pressure, but a component is worn because it is not getting enough lubrication, look at the passage for oil supply to that component. A restriction in a supply passage will not let enough lubrication get to a component and this will cause early wear.

Turbocharger Lubrication Valve

When the gauge for oil pressure shows the correct oil pressure and bearing failure or wear is present in the turbocharger, check the operation of the turbocharger lubrication valve. The valve can be in the open position and permit oil that is not clean to give lubrication to the turbocharger.

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 (too hot) point of water. The second advantage is that this type system prevents cavitation (air at inlet of pump) in the water pump. With this type system it is more difficult for an air or steam pocket to form in the cooling system.

The cause for an engine getting too hot is generally because regular inspections of the cooling system were not done. Make a visual inspection of the cooling system before testing with testing equipment.

Visual Inspection Of The Cooling System

1. Check coolant level in the cooling system.

2. Look for leaks in the system.

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

4. Inspect the drive belt 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 pressure cap and the sealing surface for the cap. The sealing surface must be clean.

Testing The Cooling System

Remember that temperature and pressure work together. When making a diagnosis 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 altitude on the boiling (too hot) point of water.

Test Tools for Cooling System

9S9102 Thermistor Thermometer Group.9S7373 Air Meter Group.1P5500 Portable Phototach Group.9S8140 Cooling System Pressurizing Pump Group.

The 9S9102 Thermistor Thermometer Group is used in the diagnosis of heating problems. The testing procedure is in Special Instruction (GMG00450).

9S9102 THERMISTOR THERMOMETER GROUP

The 9S7373 Air Meter Group is used to check the air flow through the radiator core. The testing procedure is in Special Instruction (GMG00203).

9S7373 AIR METER GROUP

The 1P5500 Portable Phototach Group is used to check the fan speed. The testing procedure is in Special Instruction (GMG00819).

1P5500 PORTABLE PHOTOTACH GROUP

The 9S8140 Cooling System Pressurizing Pump Group is used to test pressure caps and pressure relief valves, and to pressure check the cooling system for leaks.

9S8140 COOLING SYSTEM PRESSURIZING PUMP GROUP

Gauge for Water Temperature

9S9102 Thermistor Thermometer Group.2F7112 Thermometer.6B5072 Bushing.

If the engine gets too hot and loss of coolant is a problem, a pressure loss in the cooling system could be the cause. If the gauge for water temperature shows that the engine is getting too hot, look for coolant leakage. If a place can not be found where there is coolant leakage, check the accuracy of the gauge for water temperature. Use the 9S9102 Thermistor Thermometer Group. This check can also be made by installing a 2F7112 Thermometer (using a 6B5072 Bushing) into the water manifold.

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NOTICE
Be careful when working around an engine if it is running.

THERMOMETER INSTALLED

Start the engine. Put a cover over part of the radiator or cause a restriction of coolant flow. The reading on the gauge for water temperature should be the same as the reading on the thermistor thermometer.

Pressure Cap

One cause for a pressure loss in the cooling system can be a bad seal on the pressure cap of the system. Inspect the pressure cap carefully. Look for damage to the seal or the sealing surface. Any foreign material or deposits on the cap, seal or sealing surface must be removed.

Temperature Regulator

The temperature that makes the 6L5851 Regulator start to open is 172 to 177°F (78 to 80°C). The regulator is to be fully open at 197°F (92°C).

The temperature that makes the 9S9160 Regulator start to open is 162 to 167°F (72 to 75°C). The regulator is to be fully open at 187°F (86°C).

The temperature that makes the 4L7615 Regulator start to open is 164 to 166°F (73 to 74°C). The regulator is to be fully open at 180°F (82°C).

1. Remove the regulator from the engine.

2. Put the regulator and a thermometer in suspension in a pan of water.

3. Put heat to the pan to get the temperature of the water hotter. Make the water move around in the pan so all of the water will be the same temperature.

4. Check the temperature of the water when the thermostat starts to open. If the regulator does not operate correctly, install a new regulator.

NOTE: When installing a regulator inspect seal for defects and change if necessary.

Basic Block

Connecting Rods And Pistons

Use the 7B7974 Piston Ring Expander to remove or install piston rings.

Use the 2B8184 Piston Ring Compressor to install pistons into cylinder block.

Tighten the connecting rod bolts in the following step sequence:

1. Put crankcase oil on threads.

2. Tighten both nuts to 75 ± 5 lb.ft. (10.4 ± 0.7 mkg).

3. Put a mark on each nut and cap.

4. Tighten each nut 60° from the mark.

The connecting rod bearings should fit tightly in the bore in the rod. If bearing joints or backs are worn (fretted), check for bore size as this is an indication of wear because of looseness.

Connecting Rod And Main Bearings

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

Projection Of Cylinder Liner

1P2397 Puller Plate.8B7548 Push Puller Crossbar and three 3H465 Plates.8S3140 Cylinder Block Counterboring Tool Arrangement.1P5510 Liner Projection Tool Group.

1. Make sure that the bore in block and the cylinder liner flange are clean.

2. Use a 1P2397 Puller Plate (5), three 3H465 Plates (1) and the crossbar (4) from the 8B7548 Push Puller, to hold the liner down with stud nuts for the cylinder head.

3. Tighten the nuts to 50 lb.ft. (6.9 mkg). Tighten the nuts evenly in four steps; 5 lb.ft. (0.7 mkg), 15 lb.ft. (2.1 mkg), 25 lb.ft. (3.5 mkg), and then to 50 lb.ft. (6.9 mkg). The distance from bottom edge of the crossbar, to the cylinder block must be the same on both sides of the cylinder liner.

4. Use a 1P5510 Liner Projection Tool Group (2) to measure liner projection. Special Instruction (GMG00623) is included with the tool.

5. Liner projection must be .006 ± .002 in. (0.15 ± 0.05 mm). The maximum difference in height of liners next to each other is .001 in. (0.03 mm). The maximum difference between high and low measurements made at four places around each liner is .001 in. (0.03 mm). Shims are available for adjustment of the liner projection.

6. Use the 8S3140 Counterboring Tool Arrangement to bore the block deeper if needed. Maximum depth of the bore is .553 in. (14.05 mm). Special Instruction (FM055228) gives an explanation of the use of the 8S3140 Counterboring Tool Arrangement.

MEASURING LINER PROJECTION
1. 3H465 Plate. 2. Dial indicator. 3. 1P2402 Block. 4. Crossbar. 5. 1P2397 Puller Plate.

Cylinder Block

The bore in the block for main bearings can be checked with the main bearing caps installed without bearings. Tighten the nuts holding the caps to the torque shown in the SPECIFICATIONS, Form No. REG01362. Alignment error in the bores must not be more than .003 in. (0.08 mm). Special Instruction (GMG00503) gives the use of 1P4000 Line Boring Tool Group to machine the main bearing bores. 1P3537 Dial Bore Gauge Group can be used to check the size of the bores. Special Instruction (GMG00981) is with the group.

1P3537 DIAL BORE GAUGE GROUP

Flywheel And Flywheel Housing

8S2328 Dial Indicator Group.

Heat the ring gear to install it. Do not heat to more than 351°F (177°C). Install the ring gear so the chamfer on the gear teeth is next to the starter pinion when the flywheel is installed.

Face Runout (axial eccentricity) of the Flywheel Housing

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

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

CHECKING FACE RUNOUT OF THE FLYWHEEL HOUSING
A. Bottom. B. Right side. C. Top. D. Left side.

2. Force the crankshaft to the rear before reading the indication at each point.

3. With dial indicator set at .000 in. (0.0 mm) 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 .012 in. (0.30 mm), 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 to the crankshaft flange so the anvil of the indicator will touch the bore of the flywheel housing at (1). Set the indicator to read .000 in. (0.0 mm) at this point.

2. Force the crankshaft to remove the clearance of the main bearing when making measurements at each point.

3. Turn the crankshaft and read the indicator at locations (2), (3), and (4).

4. The difference between lower and higher measurements taken at all four points must not be more than .012 in. (0.30 mm), which is the maximum permissible bore runout (radial eccentricity) of the flywheel housing.

CHECKING BORE RUNOUT OF THE FLYWHEEL HOUSING
1. Bottom. 2. Right side. 3. Top. 4. Left side.

Face Runout (axial eccentricity) of the Flywheel

1. Install the dial indicator as shown. Force the crankshaft the same way before the indicator is read so the crankshaft end clearance (movement) is always removed.

2. Set the dial indicator (3) to read .000 in. (0.0 mm).

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

4. The difference between the lower and higher measurements taken at all four points must not be more than .006 in. (0.15 mm), which is the maximum permissible face runout (axial eccentricity) of the flywheel.

CHECKING FACE RUNOUT OF THE FLYWHEEL
1. 8S2329 Base and 8S2327 Post. 2. 7H1945 Holding Rod. 3. 7H1942 Indicator.

Bore Runout (radial eccentricity) of the Flywheel

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

2. Set the dial indicator to read .000 in. (0.0 mm).

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

4. The difference between the lower and higher measurements taken at all four points must not be more than .006 in. (0.15 mm), which is the maximum permissible bore runout (radial eccentricity) of the flywheel.

5. Runout (eccentricity) of the bore for the pilot bearing for the flywheel clutch, must not exceed .005 in. (0.13 mm).

CHECKING BORE RUNOUT OF THE FLYWHEEL
1. 7H1945 Holding Rod. 2. 8S2329 Base and 8S2327 Post. 3. 7H1940 Universal Attachment. 4. 7H1942 Indicator.

CHECKING PILOT BEARING BORE OF THE FLYWHEEL CLUTCH
1. 7H1945 Holding Rod (7H1645 Holding Rod in addition for aluminum or large diameter housings). 2. 8S2329 Base and 8S2327 Post. 3. 7H1940 Universal Attachment. 4. 7H1942 Indicator.

Vibration Damper

Damage to or failure of the damper will cause an increase in vibrations and can result in damage to the crankshaft.

A viscous type damper that is bent or has damage can cause weight (1) to hit case (3). This will cause a restriction in the movement of the weight and cause an increase in vibrations.

The damper needs replacement when the holes for the bolts have wear and the fit between the bolts and the holes is loose.

TYPICAL VISCOUS TYPE DAMPER
1. Solid cast iron weight. 2. Space between weight and case. 3. Case.

Electrical System

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

Battery

9S1990 Battery Charger Tester.

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 will result, if the connections, (either positive or negative) between the battery and charging unit are broken while the charging unit is charging. This is because the battery load is lost and there is an increase in charging voltage.

High voltage will damage, not only the charging unit but also the regulator and other electrical components.

9S1990 BATTERY CHARGER TESTER

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NOTICE
Never disconnect any charging unit circuit or battery circuit cable from battery when the charging unit is charging.

Load test a battery that does not hold a charge when in use. To do this, put a resistance, across the battery main connections (terminals). For a 6 volt battery, put a resistance of two times the ampere/hour rating of the battery. For a 12 volt battery, put a resistance of three times the ampere/hour rating. Let the resistance remove the charge (discharge the battery) for 15 seconds. Immediately test the battery voltage. A 6 volt battery in good condition will test 4.5 volts; a 12 volt battery in good condition will test 9 volts.

The Special Instruction (GEG00058) with the 9S1990 Charger Tester gives the battery testing procedure.

Charging System

The condition of charge in the battery at each regular inspection will show if the charging system is operating correctly. An adjustment is necessary when the battery is always in a low condition of charge or a large amount of water is needed (one ounce per cell per week or every 50 service hours).

Test the charging units and voltage regulators on the engine, when possible, using wiring and components that are a permanent part of the system. Off the engine (bench) testing will give an operational test of the charging unit and voltage regulator. This testing will give an indication of needed repair. Final testing will give proof that the units are repaired to their original operating condition.

Before starting on the engine testing, the charging system and battery must be checked. See the following Steps.

1. Battery must be at least 75% (1.240 Sp. Gr.) full charged and held tightly in place. The battery holder must not put too much stress on the battery.

2. Cables between the battery, starter 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 proper circuit control.

4. Inspect the drive components for the charging unit to be sure they are free of grease and oil and are able to drive the load of the charging unit.

Alternator Regulator (Motorola)

REGULATOR ADJUSTMENT

To make an increase to the voltage (approximately .4 volt on a 12 volt system or .6 volt on a 24 volt system) remove the locknuts from the two terminals that are nearer the word "HI" than the other terminals. Put the metal strap over these terminals, put the locknuts on the terminals and tighten the locknuts.

To make the voltage lower (approximately .4 volt on a 12 volt system and .6 volt on a 24 volt system) put the metal strap on the two terminals nearer the word "LO".

Alternator Regulator (Delco-Remy)

When an alternator is charging the battery too much or not enough, an adjustment can be made to the alternator regulator. Remove the plug from the cover of the alternator regulator and turn the inside adjustment with a screwdriver. Turn the adjustment one or two notches to change the alternator charging rate.

ALTERNATOR REGULATOR
1. Adjustment screw, on other side of alternator from output terminal.

5S9088 Alternator; Pulley Nut Tightening

ALTERNATOR PULLEY INSTALLATION
1. 8S1588 Adapter (1/2" female to 3/8" male). 2. 8S1590 Socket (5/16"-3/8" drive). 3. 1P2977 Tool Group. 8H8555 Socket (15/16"-1/2" drive) not shown.

Tighten nut holding the pulley to a torque of 75 ± 5 lb.ft. (10.4 ± 0.7 mkg) with the tools shown.

Starting System

Use a D. C. Voltmeter to find starting system components which do not function.

Move the starting control switch to activate the starter solenoid. Starter solenoid operation can be heard as the pinion of the starter motor is engaged with the ring gear on the engine flywheel. The solenoid operation also closes the electric circuit to the motor. Connect one lead of the voltmeter 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 voltmeter. A reading of battery voltage shows the problem is in the motor. The motor must be removed for further testing. No reading on the voltmeter 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. Pinion clearance is .36 in. (9.1 mm).

If the solenoid for the starting motor will not operate, it is possible that the current from the battery is not getting to the solenoid. Fasten one lead of the voltmeter to the connection (terminal) for the battery cable on the solenoid. Put the other lead to a good ground. No voltmeter reading shows there is a broken circuit from the battery. Further testing is necessary when there is a reading on the voltmeter.

Further test by fastening one voltmeter lead to the connection (terminal) for the small wire at the solenoid and the other lead to the ground. Look at the voltmeter and activate the starter solenoid. A voltmeter reading shows that the problem is in the solenoid. No voltmeter reading shows that the problem is in the starter switch or wiring. Fasten one lead of the voltmeter to the battery wire connection of the starter switch and put the other lead to a good ground. A voltmeter reading indicates a failure in the 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 shorts, loose connections, and/or dirt in the motor.

Pinion Clearance Adjustment (Delco-Remy)

Whenever 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. Connector from MOTOR terminal on solenoid to motor. 2. SW terminal. 3. Ground terminal.

1. Install the solenoid without connector (1) from the MOTOR connection (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 battery to ground terminal (3).

PINION CLEARANCE ADJUSTMENT
4. Shaft nut. 5. Pinion. 6. Pinion clearance.

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.

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

6. Pinion clearance (6) must be .36 in. (9.1 mm).

7. Pinion clearance adjustment is made by removing plug and turning nut (4).

Safety Control Shutoff

Overspeed Control Adjustment

Adjustment of the overspeed control is made at the factory and must not be changed unless the carrier assembly has been disassembled or the adjustment changed in some way. The original setting of the overspeed control is to stop the engine when the engine rpm is more than 18% above full load rpm.

On Engine Adjustment

The adjustment is made by removing the plug from the bottom of the shutoff housing to get to the weight adjustment screw. If necessary, turn the flywheel until the adjustment can be made with a screwdriver as shown.

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NOTICE
Be sure to turn the flywheel in the direction of normal rotation. If the flywheel is turned in the wrong direction it is possible to cause damage to the worm shaft and slide follower.

ADJUSTMENT OF THE WEIGHT SPRING TENSION

One full turn of the adjustment screw will change the speed setting 45 to 50 rpm. Clockwise turning of the adjustment screw will increase the pressure on the spring and will increase the maximum speed limit. Counterclockwise turning of the screw will cause a reduction in the pressure on the spring and lower the maximum speed limit.

Off Engine Adjustment

4S6553 Engine Test Group.FT907 Drive Adapter.Reversible variable speed drill.

The FT907 Adapter (C) with a reversible variable speed drill (D) and tachometer are used for adjustment of the control.

1. Connect the 1P7443 or 4S6991 Tachometer (part of the 4S6553 Engine Test Group) to the tachometer drive on the control (A).

2. Use the FT907 Adapter and variable speed drill to drive the control as shown.

NOTE: If adjustment or check of the overspeed control is made and the oil pressure reset plunger is not pushed in, a low oil pressure shutoff action will be the result.

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NOTICE
All safety shutoff controls must be driven counterclockwise.

3. Read the speed on the tachometer at the moment the control is activated. The reading will give the engine speed (2 rpm on the scale for each rpm the input shaft is turned).

4. The control is to activate at a speed 18% higher than the full load rpm.

TESTING OVERSPEED CONTROL
A. Safety control. B. 4S6553 Engine Test Group. C. FT907 Adapter. D. Reversible variable speed drill.

5. Make adjustment if needed by turning the weight adjustment screw, setting the release rod and again testing until the correct adjustment is made.

Woodward UG-8 Governor

Adjustments

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NOTICE
Fuel rack setting is done carefully at the factory. Do not change the fuel rack setting unless it is known to be wrong. A wrong setting of the fuel rack can cause a problem with the turbocharger. Make reference to the book RACK SETTING INFORMATION for the correct rack setting.

Governor Linkage Adjustment

1. Put lever (1), for the terminal shaft of the governor, on the shaft in the position shown. The terminal shaft must be in the fuel closed position.

2. Put lever (3) on the shaft.

3. Make an adjustment to the length of rod (2) so that it can be installed when levers (1 and 3) are in the off position as shown.

WOODWARD GOVERNOR LINKAGE
1. Lever. 2. Rod. 3. Lever. A. 2.188 in. (55.58 mm) length of lever (1). B. 2.375 in. (60.33 mm) length of lever (3).

WOODWARD GOVERNOR LINKAGE INSTALLED
1. Lever. 2. Rod. 3. Lever.

Low Or High Idle Speed Adjustment

Check the engine LOW or HIGH IDLE rpm at the connection for tachometer drive. Make this check with a hand tachometer. The rotation of the tachometer drive is one half of engine rpm.

GOVERNOR ADJUSTMENTS (With Dial Plate Removed)
1. Lever. 2. Idler gear. 3. Load limit knob. 4. Rod. 5. Synchronizer knob. 6. Gear. 7. Synchronizer indicator knob.

1. Put the load limit knob (3) at point 5 to keep the engine from getting too much fuel and having a rapid increase in speed.

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NOTICE
To have a method of stopping the engine if it runs too fast, do the following:

a. Disconnect the linkage (8) for the overspeed control at lever (9).

PLACE TO DISCONNECT LINKAGE
8. Linkage. 9. Lever.

b. Have your hand on lever (9) and be ready to move the lever to the STOP position.

LEVER IN RUN POSITION
9. Lever.

c. If the engine speed goes too high, move lever (9) to the STOP position.

2. Start the engine and slowly make an increase to the amount of fuel. When the engine is at the operating temperature, slowly turn the load limit knob (3) from 5 to 10. Use the synchronizer knob (5) to make an adjustment to the engine speed; then, check the low or high idle stop.

LEVER IN STOP POSITION
9. Lever.

3. If the low or high idle stop does not permit the correct speed, an adjustment is necessary. Remove the dial plate.

4. Loosen the set screw on synchronizer indicator knob (7) and remove the knob.

5. Pull gear (6) out so it is not engaged with gear (2).

6. When making an adjustment of the high idle speed, turn synchronizer knob (5) clockwise until the engine is at the correct high idle speed. Turn the knob counterclockwise when making the adjustment of the low idle speed.

7. To make an adjustment of the stop for the high idle speed, turn gear (6) clockwise (counterclockwise for low idle speed) until the pin in the gear is in contact with idler gear (2). Engage the gears.

8. After the adjustment to the idle speed has been made, turn the synchronizer knob to change the speed of the engine. Then turn it to the stop position and check the idle speed. If necessary, make the adjustment again.

NOTE: If necessary, make an adjustment to the synchronizer indicator pointer disc. With the engine running at high idle, stop the engine by turning load limit knob (3) to zero. Remove the synchronizer indicator pointer disc and again install it so the pointer on the disc will point to 12 on the dial plate. This will give high idle stop position.

9. Install synchronizer indicator knob (7) and the dial plate.

Fuel Rack Setting

Use the same tools and procedure to make an adjustment of the fuel rack as shown for the mechanical governor, make reference to FUEL RACK SETTING.

Compensating Adjustment

The governor can show signs of operating correctly at no load, but have high over speeds and under speeds and be slow to return to normal speed after load changes. These conditions are the result of wrong compensation adjustments.

Make the following adjustments to be sure the governor will give the desired control.

After the engine and the oil in the governor are at the normal operating temperature, make the adjustments with no load on the engine.

1. Loosen nut (1) and put compensating adjustment pointer (2) at MAX. Tighten nut (1).

2. Remove plug (3) and use a screwdriver to open the compensating needle valve three or more turns.

3. Permit the engine to run rough for approximately 30 seconds to remove the air from the oil passages in the governor. Loosen nut (1) and put pointer (2) at MIN. Tighten nut (1). Slowly turn the compensating needle valve in until the rough running stops. It must take less than one turn from this point to completely close the needle valve.

4. Open the needle valve to the same position where the rough running stopped.

5. Move the governor terminal shaft manually to make an increase in engine rpm, then let go of the lever and permit the operation of the governor to stabilize.

COMPENSATING ADJUSTMENT
1. Nut. 2. Compensating adjustment pointer. 3. Plug.

6. If the engine speed stabilizes, and the needle valve is only 1/2 to 3/4 turn open, the governor is properly adjusted. Install plug (3).

NOTE: If more than 3/4 turn is necessary to stop the engine from running rough, raise the compensation adjustment pointer (2) two points above MIN and do Steps 2 thru 6 again.

7. A needle valve opened less than 1/2 turn causes a slow response to load change. A needle valve opened more than 3/4 turn causes excessive speed response to load change. If engine does not stabilize between 1/2 and 3/4turn open, raise pointer (2) two more points above MIN and do Steps 2 thru 6 again.

8. When engine speed stabilizes, install plug (3).