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.

Troubleshooting Index

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. 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 Hr 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.

Engine Crankshaft Will Not Turn When Start Switch Is On

Engine Will Not Start

Misfiring Or Running Rough

Stall At Low RPM

Sudden Changes In Engine Speed (rpm)

Not Enough Power

Too Much Vibration

Loud Combustion Noise (Sound)

Valve Train Noise (Clicking)

Oil In Cooling System

Mechanical Noise (Knock) In Engine

Fuel Consumption Too High

Loud Valve Train Noise

Too Much Valve Lash

Valve Rotocoil Or Spring Lock Is Free

Oil At The Exhaust

Little Or No Valve Clearance

Engine Has Early Wear

Coolant In Lubrication Oil

Too Much Black Or Gray Smoke

Too Much White Or Blue Smoke

Engine Has Low Oil Pressure

Engine Uses Too Much Lubrication Oil

Engine Coolant Is Too Hot

Starting Motor Does Not Turn

Alternator Gives No Charge

Alternator Charge Rate Is Low Or Not Regular

Alternator Charge Too High

Alternator Has Noise

Exhaust Temperature Is 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 Fuel Pump Plunger and Lifter Yoke

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 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.

Fuel Bypass Valve

The fuel bypass valve controls fuel pressure to the fuel injection pump at full speed to a pressure of 25 to 35 psi (170 to 240 kPa).

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. (142 ± 7 N·m). There will be damage to the nozzle if the nut is too tight. If the nut is not tight enough the nozzle can leak.

Removal of 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. 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 lift out 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 is damaged install a new one.

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 rack mark (5).

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

4. Slide 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. Put 8H5137 Form A Gasket on bolt threads. Tighten bolts (8) first and then tighten bolts (7). Torque for bolts (7) and (8) is 32 ± 5 lb. ft. (43 ± 7 N·m). Tighten the fuel line nuts to 30 ± 5 lb. ft. (40 ± 7 N·m) with a 5P144 Fuel Line Socket.

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

Finding Top Center Compression Position For No. 1 Piston

2P8300 Engine Turning Tool Group or5P7307 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 the valve and rocker arm cover (the two valves at the front are the intake and exhaust valves for No. 1 cylinder).

2. Remove the timing mark cover from the top of the flywheel housing.

3. Turn the flywheel in the direction of engine rotation until No. 1 piston is at TC (top center) on compression stroke. Indication is by flywheel pointer (1). On compression stroke, both valves will be closed.

TIMING MARKS ON FLYWHEEL
1. Pointer.

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

2P8300 ENGINE TURNING TOOL GROUP
2. 2P8294 Housing. 3. 2P8299 Pinion.

Checking The Timing Of The Fuel Injection Pump Housing; On Engine

Checking with 1P540 Flow Checking Tool Group

1P540 Flow Checking Tool Group.5P6524 or 3S2954 Timing Indicator Group.9S215 or 9M9268 Dial Indicator.5P7306 or 2P8294 Housing.5P7305 or 2P8299 Pinion.

Check the timing of the camshaft for the fuel injection pumps to see if it is necessary to make an adjustment for a loose coupling or worn timing gears. See Special Instruction (SMHS7083) for complete instructions for the fuel flow method of engine timing (injection sequence).

MEASURING PISTON TRAVEL (3S2954 Timing Indicator Group Shown)
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, can be found by using the 5P6524 or 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 tank assembly to get 10 to 15 psi (70 to 105 kPa) fuel pressure.

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Be sure to make an adjustment to the regulator so the air supply in the tank is a maximum of 15 psi (105 kPa).

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 6 to 12 drops per minute [point of closing inlet port (5)].

If the correct indicator reading is not on the dial indicator, it is possible that the camshaft for the fuel injection pumps needs timing. See, TIMING THE CAMSHAFT FOR THE FUEL INJECTION PUMPS. Several cylinders can be checked, and if there is a difference in the readings remove the fuel pump housing so all lifter settings can be checked and an adjustment made. See, FUEL PUMP LIFTER SETTING; OFF ENGINE.

Checking with 6F6922 Micrometer Depth Gauge

Turn the crankshaft and flywheel to top center compression position for No. 1 piston. This is with pointer (1) pointing to No. 1 TC as shown in topic FINDING TOP CENTER COMPRESSION POSITION FOR NO. 1 PISTON.

Check the pump lifter setting when at this position with the 6F6922 Micrometer Depth Gauge.

MEASURING LIFTER SETTING DIMENSION
2. Distance to be measured.

The reading should be the "ON ENGINE" lifter setting dimension of 2.090 ± .002 in. (53.09 ± 0.05 mm).

If the correct reading is not measured, it is possible that the camshaft for the fuel injection pumps needs timing. See, TIMING THE CAMSHAFT FOR THE FUEL INJECTION PUMPS. Several cylinders can be checked, and if there is a difference in the readings, remove the fuel pump housing so all lifter settings can be checked and adjustments made. See, FUEL PUMP LIFTER SETTING; OFF ENGINE.

Timing The Camshaft For The Fuel Injection Pumps

FLYWHEEL TIMING MARKS
1. Flywheel pointer.

1. Find top center compression position for No. 1 piston. This is with pointer (1) pointing to No. 1 TC as shown.

TIMING MARK ON CAMSHAFT GEAR
2. Cover. 3. "V" mark. 4. Hole in housing for timing gears.

2. Remove the covers from the side of the housing for the fuel pump and governor drive shaft.

3. Remove the cover (2) for the gear for the camshaft.

4. Remove the dowel (8) from the hole (5) and install it in hole as shown. If the camshaft for the injection pump housing is in time, the dowel (8) will engage the slot (9) and the "V" mark (3) will be in line with hole (4) in housing for timing gears.

To time the camshaft, loosen bolts (7) and turn the camshaft for the fuel injection pump until the dowel (8) can be installed to engage slot (9). To turn the camshaft, put a small punch in one of the holes (10).

TIMING THE CAMSHAFT FOR THE FUEL INJECTION PUMP HOUSING
5. Hole. 6. Coupling. 7. Bolts. 8. Dowel. 9. Slot. 10. Hole.

Fuel Pump Lifter Setting; Off Engine

5P6600 or 1P5600 Tool Group.6F6922 Gauge or5P4165 Dial Indicator Group.

The following procedure is for checking the lifters with the pump housing off the engine.

5P6600 TOOL GROUP
Tools listed are needed out of the 5P6600 Tool Group to make OFF ENGINE lifter setting. 1. 1P7410 Plate. 2. 5P6568 Shaft. 3. 9M4568 Wrench. 4. 9M4567 Wrench. 5. S1594 Bolt. 6. S509 Bolt. 7. 1P7415 Pointer. 8. 2S6160 Washer.

OTHER TOOLS NEEDED
9. 5P4165 Dial Indicator Group. 10. 4B7617 Wrench. 12. 6F6922 Micrometer. 13. 4B7618 Wrench.

1. Connect timing plate (1) to the drive end of the camshaft using shaft (2), bolt (6) and washer (8). Alignment of the key in shaft (2) with the keyway in the camshaft 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 in the top of the pump housing and fasten it in place.

3. Find in the chart the timing plate degree for the lifter being checked or needing an adjustment. Turn the timing plate to this degree mark by turning it clockwise until the correct degree mark is in alignment with the inside edge (11) of pointer (7).

4. Use depth gauge (12) or dial indicator (9) to measure the fuel pump lifter setting (dimension A). This dimension is the distance from the flat surface on the top of the housing to the plunger contact surface in the yoke of the lifter. If necessary, use a 9M4568 Wrench (3) and a 9M4567 Wrench (4) to make dimension (A) adjustment. The adjustment must be the "OFF ENGINE" lifter setting dimension of 2.156 to 2.157 in. (54.76 to 54.79 mm).

FUEL PUMP LIFTER SETTING (OFF ENGINE)
1. 1P7410 Timing Plate. 7. 1P7415 Pointer. 11. Edge of pointer. 12. 6F6922 Micrometer Depth Gauge. A. Dimension to be measured.

NOTE: To get a correct measurement, be sure the flat surface on top of the housing for the fuel pump is clean, dry and free of paint.

5. If all lifters are to be checked or an adjustment made to them, use the same procedure in the firing order (injection sequence) of the engine. Check each lifter setting again after the adjustment has been made and the locknut tightened to make sure the adjustment has not changed. Fuel injection pumps are numbered in order from front to rear of the housing. FIRING ORDER (Injection Sequence) for this engine is 1-5-3-6-2-4.

Fuel Rack Setting - (Hydra-Mechanical Governor)

9S240 Rack Positioning Tool Group.

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NOTICE
Rack setting is carefully set at the factory and must not be changed unless it is known to be wrong. A wrong setting of the fuel rack will cause a problem with the turbocharger.

PARTS OF 9S240 RACK POSITIONING TOOL GROUP
1. 5S8090 Rod Assembly. 2. 8S2283 Dial Indicator. 3. 9S239 Adapter. 4. 3S3268 Point. 5. 8S4627 Circuit Tester.

1. See the RACK SETTING INFORMATION to find the correct rack setting dimension.

PREPARING TO ADJUST THE FUEL RACK
6. Bolt.

2. With engine stopped, disconnect the governor control linkage at the most convenient location, so the governor control lever (7) moves freely. Remove bolt (6) and cover (8).

PREPARING TO ADJUST THE FUEL RACK
7. Governor control lever. 8. Cover.

3. Move governor control to the FUEL CLOSED position. Install adapter (3) and dial indicator (2). Adjust the dial indicator so the reading is minus .525 inches and tighten the dial indicator in place.

TOOLS INSTALLED
2. 8S2283 Dial Indicator with 3S3268 Contact Point. 3. 9S239 Adapter with 5S8090 Rod Assembly. 5. Circuit Tester.

4. Attach the wire clip end of tester (5) to the brass screw terminal on the governor housing and ground the other end.

5. Move the governor control lever against the speed limiter.

6. Using a pry bar or similar tool, push the rack away from the governor through the hole in the pump and governor drive housing to the FUEL CLOSED position.

7. Adjust the dial of the dial indicator so the reading is minus .525 inches and tighten the dial in place.

8. Gradually release the pressure from the end of the fuel rack and allow the rack to move towards the FUEL OPEN position until the light just shows (a dim light). The adjustment screw in the rack collar is now just coming in contact with the stop bar. The rack setting dimension is read from the dial indicator (2).

9. To make an adjustment to the rack setting, remove the hydraulic air fuel ratio control.

10. Loosen the locknut (9) and using wrench (10) make an adjustment to the screw to get the correct rack setting dimension. Continue adjustment procedure until the reading on the dial indicator is the same as the setting given in the RACK SETTING INFORMATION.

NOTE: Turn screw clockwise to make a decrease in the rack travel. Never make an adjustment to the rack travel by adding or removing shims.

11. When the correct adjustment has been made to the rack, tighten the locknut (9) to 9 ± 3 lb. ft. (12 ± 4 N·m).

MAKING AN ADJUSTMENT TO THE RACK SETTING
9. Nut. 10. 9S1742 Hex Key Wrench Assembly.

12. Install the hydraulic air fuel ratio control, and cover (8).

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NOTICE
Do not pull up on the rack stop collar while measuring the fuel setting. This moves the governor hydraulic components to the wrong position and results in about a .050 in. (1.27 mm) error in the reading. The bumper spring under the rack stop collar has enough force to move the collar.

Fuel Rack Setting - (Mechanical Governor)

9S240 Rack Positioning Tool Group

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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 adjustment of the fuel rack setting can cause a problem with the turbocharger. Make reference to the RACK SETTING INFORMATION for the correct rack setting dimension.

Refer to Form SEHS6995 for instructions for use of tools needed to check and make adjustment to the fuel rack setting.

9S240 RACK POSITIONING TOOLS FOR FUEL RACK SETTING
1. 9S7343 Bracket. 2. 9S7344 Clamp. 3. 8S2283 Dial Indicator. 4. 3S3268 Contact point.

1. Remove the seal and cover (5) for the governor, disconnect any linkage from the control lever (7) for the governor and remove the cover (6).

GOVERNOR
5. Cover. 6. Cover. 7. Control lever.

2. Fasten the 9S7343 Bracket Assembly (1) to the housing and the 9S7344 Clamp Assembly (2) to the rack at a point .12 in. (3.0 mm) from the mark on the rack as shown.

3. Install 8S2283 Dial Indicator (3) and make an adjustment to the indicator setting so it reads minus .523 when the rack is in the fuel closed position. Tighten the bolt to hold the indicator.

4. Move the control lever (7) for the governor to the fuel on direction until adjustment screw (8) makes contact with the torque spring or stopbar. Read the dial indicator.

TOOLS IN PLACE FOR RACK SETTING
1. Bracket. 2. Clamp. 3. Dial indicator.

NOTE: When a torque spring is between the adjustment screw and stop bar, put a thickness gauge the same thickness as the spacer between the spring and stop to prevent movement of the spring.

5. Turn the adjustment screw (8) clockwise to decrease the rack setting, or counterclockwise to increase the setting. Put the lock in to position with the nearest groove over the lock pin and tighten the locknut (9).

RACK ADJUSTMENT
7. Control lever. 8. Adjustment screw. 9. Locknut.

NOTE: The 3H1690 Gauge can also be used to make the rack setting.

Governor Adjustment - (Hydra-Mechanical Governor)

5P1759 Tachometer Drive Adapter.4S6553 Engine Test Group.

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NOTICE
A shop man with training in governor adjustments is the only one to make an adjustment to the low idle and high idle rpm. The correct low idle and high idle rpm and the measurement for the fuel rack are given in the RACK SETTING INFORMATION.

1. Remove the service meter (1) and install the 5P1759 Tachometer Drive Adapter.

REMOVE SERVICE METER
1. Service meter.

2. Remove cover (4) on the governor. Adjustments can be made by turning the low idle (2) and high idle (3) adjustment screws. Turning either adjustment screw clockwise will cause a decrease to the respective low and high idle rpm. The retainer holes in the cover keep the screws from turning after the adjustment is made.

GOVERNOR ADJUSTMENT
2. Low idle adjustment screw. 3. High idle adjustment screw. 4. Cover.

3. After making the adjustment to the idle rpm, move the governor control lever to change the engine rpm. Move lever back to the idle position and check the idle rpm again. Make the adjustment using this method until the idle rpm shown in the RACK SETTING INFORMATION is constant.

Hydraulic Air Fuel Ratio Control Setting - (Hydra-Mechanical Governor)

1. Check the fuel rack setting. Make reference to FUEL RACK SETTING. The fuel rack setting must be correct before the adjustment for the hydraulic air fuel ratio control can be checked or changed.

HYDRAULIC AIR FUEL RATIO CONTROL
1. Cover.

2. Remove the cover (1) from the hydraulic air fuel ratio control.

NOTE: The adjustment of the hydraulic air fuel ratio control requires two people. One to operate the controls and apply a load, the other to read the dial indicator and make the adjustment.

3. Start the engine.

SETTING HYDRAULIC AIR FUEL RATIO CONTROL
2. Valve. 3. Pin.

4. Push the end of valve (2) in and hold it in for two or three seconds. This action will manually move the valve into its operating position.

5. Apply a load to the engine.

6. Move the governor control lever from the FUEL CLOSED to the FUEL OPEN position several times to remove the air from the control for a more accurate reading.

7. Rapidly move the governor control lever in the FUEL OPEN direction and read the measurement on the dial indicator (4) carefully. This reading will be a maximum for only a moment. The correct reading is the RACK SETTING INFORMATION.

READING HYDRAULIC AIR FUEL RATIO SETTING
4. Dial indicator.

8. To make an adjustment to the hydraulic air fuel ratio control, turn valve (2) in a clockwise direction to make an increase in the limited rack position and in a counterclockwise direction to make a decrease in the limited rack position.

9. After each adjustment is made, the governor control lever must be moved from the FUEL CLOSED to the FUEL OPEN direction before an accurate reading can be made.

10. After the correct adjustment has been made, put cover (1) in alignment with pin (3) and turn cover to put it in alignment with the nearest bolt holes. Install bolts.

11. Stop the engine.

12. After the oil pressure has gone out of the hydraulic air fuel ratio control, full rack travel must be available. The speed limiter plunger will have to be pushed in to permit full rack travel.

13. Remove dial indicator (4) and install bolt. Install the wire and seal on the control.

Governor Adjustments - (Mechanical Governor)

7M6001 Tachometer Drive Adapter Group.

The engine idle speed can be checked at the tachometer drive outlet on the service meter. The indication will be one-half engine speed.

SERVICE METER TACHOMETER DRIVE OUTLET

Remove cover (4) from the top of the governor and make an adjustment to the high and low idle speeds.

To increase the high and low idle speeds turn the screws (1) and nut (3) counterclockwise. Screw (1) is used to make adjustment to the high idle speed and nut (3) is used to make adjustment to the low idle speed. The shape of holes (2) in cover (4) prevents the screws from turning after the cover is installed.

After making an idle speed adjustment, move the governor control lever away from the speed setting. Then move it back to the desired idle position and again check the idle speed. Do this procedure again and if necessary again make an adjustment to the idle speed.

GOVERNOR ADJUSTMENTS
1. High idle screw. 2. Retainer holes. 3. Low idle nut. 4. Cover.

Timing The Camshaft Gear

TIMING THE CAMSHAFT
1. "F" mark on gear for accessory shaft. 2. Idler gear for the camshaft. 3. Mark on gear for the accessory shaft. 4. "F" mark on the crankshaft gear. 5. Mark on gear for the accessory shaft.

1. Make sure the No. 1 piston is at TC (top center) on compression position.

2. Make alignment of "F" mark (1) on the gear for the accessory drive shaft, and the "F" mark (4) on the gear for the crankshaft.

3. Install a 3/8 in. NC-16 bolt between the two teeth of the camshaft gear at the "V" mark (7). Tighten the bolt in to the hole in the housing. This holds the camshaft in No.1 cylinder top center compression position.

NOTE: It may be difficult to see the "F" marks when the thrower is on the crankshaft. For this reason marks (3) and (5) are put on the gear for the accessory shaft and will be in alignment with the outside diameter of the thrower. A notch in the face of the accessory gear at the "F" mark (1) location gives clearance to see the dash mark on the chamfer of the crankshaft gear tooth at "F" mark (4).

4. Install the gear for the governor drive shaft.

5. Install the idler gear (2) for the camshaft.

6. Remove the bolt installed in step (3).

TIMING MARKS
6. Idler gear for the camshaft. 7. "V" mark.

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 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 RACK SETTING INFORMATION. Development of this information is done with these conditions: 29.4 in. (746.76 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 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 RACK SETTING INFORMATION. If the fuel is rated below 35 API, the pressure in the inlet manifold can be more than given in the 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 Instructions (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. 1P7447 Gauge. 5. Pressure tap fitting. 6. 1P7443 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 or5P7307 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.

NOTE: The following test cannot be used with engines that have pistons with keystone rings. Pistons with keystone rings were effective in production with engine Serial Numbers 46B5725-UP and 47B4017-UP.

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 or 5P7307 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. The 5S1322 Valve Keeper Installer with the compressor assembly makes 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 Clearance Setting

To make an adjustment to the valve clearance, turn adjusting screw in the rocker arm. Valve clearance adjustments can be made by using the following procedure:

CHECKING VALVE CLEARANCE

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 clearance on the intake valves for cylinders 1, 2, and 4. Make an adjustment to the valve clearance on the exhaust valves for cylinders 1, 3, and 5.

3. Turn the flywheel 360° in the direction of engine rotation. This will put No.6 piston at top center (TC) on the compression stroke.

4. Make an adjustment to the valve clearance on the intake valves for cylinders 3, 5, and 6. Make an adjustment to the valve clearance on the exhaust valves for cylinders 2, 4, and 6.

5. After valve adjustment is correct, tighten the nuts for valve adjustment screws to 40 ± 5 lb. ft. (55 ± 7 N·m).

Valve Seat Inserts

Larger than original size valve seat inserts are available.

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. Use the 5P3536 Valve Guide Measuring Group to check the valve guides for wear. Instructions are in Special Instruction (GMG02562).

The 4H446 Driver and 5P1726 Bushing is used for installation of new valve guides.

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. Ferrule. 3. Seal.

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

Replacement type seals (3) and ferrule (2) go between the head and top of the block. Put soap on the inner surface of the seal and put the seal on the ferrule. 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.

Precombustion Chamber

Use the 5F9217 Tool Group to remove and install chamber. Put 9M3710 Anti-Seize Compound on the threads and use either 1P8005 or 1P8004 gasket to position precombustion chamber.

Install 1P8004 Gasket with "3D" on it. Install precombustion chamber and tighten to torque of 225 ± 15 lb. ft. (300 ± 20 N·m). If the glow plug opening is not positioned in the GO RANGE "A" remove the chamber and replace gasket with the 1P8005 Gasket with "3J" on it.

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.

OIL PRESSURE IS LOWOIL PRESSURE IS HIGHTOO MUCH COMPONENT WEAR

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 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 not installed correctly.

4. There can be a leakage of oil past the ring seals at the impeller end of the turbocharger shaft.

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 210 ± 10° F (100 ± 6° C), the oil pressure measured at the clean side of oil filter at the filter base will be 36 to 56 psi (250 to 385 kPa).

A lower pressure reading of approximately 18 psi (125 kPa), is normal at low idling speeds. An 8M2744 Gauge, which is part of 5P6225 Hydraulic Test Box, can be used for checking pressure in the system.

5P6225 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 (1) 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 valve (1) in the oil filter, causes oil to go around the filter elements when there is a reduction in flow through the elements.

OIL FILTER BYPASS VALVE
1. Bypass valve.

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 Component 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 and speed limiter operation 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 open and allow unfiltered oil to constantly lubricate the turbocharger.

TURBOCHARGER LUBRICATION VALVE AT RIGHT FRONT OF ENGINE

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.

8. Look for large amounts of dirt in the radiator core and on the engine.

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.

9S9102 THERMISTOR THERMOMETER GROUP

The 9S9102 Thermistor Thermometer Group is used in the diagnosis of heating problems. The testing procedure is in Special Instruction (SMHS7140).

Gauge for Water Temperature

9S9102 Thermistor Thermometer Group.

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 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.

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

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.

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 (SMHS7015).

1P5500 PORTABLE PHOTOTACH GROUP

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.

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

Water Temperature Regulator

The regulator must be fully open at the following temperature:

6N4540 Regulator ... 197° F(92° C)

6L6108 Regulator ... 200° F(93° C)

Test Procedure:

1. Heat water in a pan until the temperature of the water is correct for opening the regulator according to the chart.

2. Hang the regulator in the pan of water so it is completely under the water. The regulator must not be in contact with the sides or bottom of the pan during the test period.

3. During the test period, move (stir) the water around the inside of the pan to make all the water the same temperature.

4. After 10 minutes at the correct temperature, take the regulator out of the water.

5. Measure immediately the distance the regulator is open. The distance must be .310 in. (7.87 mm) or more.

6. Use a new regulator if the old regulator does not open correctly.

Basic Block

Connecting Rods And Pistons

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NOTICE
Do not install the new 7N5035 Piston, which is part of 7N5037 Piston Group, into a cylinder liner that has been used with earlier pistons unless you remove the wear ridge that is toward the top of the cylinder liner. The position of the top ring of the new piston is .040 in. (1.02 mm) higher (nearer the top of the piston) than it was on the former pistons. If the wear ridge is not removed, the result will be immediate damage to the top ring or the piston at the time the engine is started. SPECIAL INSTRUCTION Form SEHS7220 gives the procedure and tools needed to remove the wear ridge in the cylinder liner.

Use the 5H9621 Piston Ring Expander to remove or install piston rings.

Use the 5P3528 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 all nuts to 75 ± 5 lb. ft. (100 ± 7 N·m).

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.

Piston Ring Groove Gauge (Pistons That Use Keystone Rings)

Make reference to GUIDELINE FOR REUSABLE PARTS; PISTONS AND CYLINDER LINERS, Form No. SEBF8001; Bulletin, Form No. SEBF8015.

The 5P4812 KEYSTONE PISTON RING GAUGE GROUP is necessary for measuring these grooves. Put the pin end of gauge "3" in the groove at four places around the circumference. Do this to both grooves. The flat edge of the gauge must be between the grooves. If there is clearance between the flat edge of the gauge and the piston at all test locations, for both grooves, the piston is reusable. If the flat edge is in contact with the piston, at any of the test locations, the piston is not reusable. Install a new piston.

5P4812 KEYSTONE PISTON RING GROOVE GAUGE GROUP

(Pistons With Straight Sides in Ring Grooves)

A 5P3519 Piston Ring Groove Gauge is available for checking ring grooves with straight sides. For instructions on the use of the gauge, see the GUIDELINE FOR REUSABLE PARTS; PISTONS AND CYLINDER LINERS, Form No. SEBF8001.

5P3519 PISTON RING GROOVE GAUGE

Cylinder Liner Projection For Engines With Spacer Plates

1P2396 Adapter Plate.8B7548 Push-Puller Crossbar and three 3H465 Plates.3/4"-10 NC Bolts, 3 in. (76.2 mm) long.3/4"-10 NC Bolts, 7 in. (177.8 mm) long.7M7875 Head Bolt Washers.8S3140 Cylinder Block Counterboring Tool Arrangement.1P5510 Liner Projection Tool Group.

Check liner projection above spacer plate (4) as follows:

1. Make certain that spacer plate (4) and the cylinder liner flange are clean.

2. Install the gasket and spacer plate (4) on the cylinder block. Use 3/4 in.-10 NC bolts, 3 in. (76.2 mm) long, with two 7M7875 Washers (3) on each bolt to secure spacer plate (4) to the cylinder block. Place two bolts with washers on each side of the cylinder liner. Tighten the bolts evenly, in four steps; 10 lb. ft. (14 N·m), 25 lb. ft. (35 N·m), 50 lb. ft. (70 N·m) and finally to 70 lb. ft. (95 N·m).

NOTE: To avoid moving bolts and washers as each liner is checked, install two bolts with washers on each side of each cylinder liner, along the entire length of the spacer plate.

SECURING SPACER PLATE TO CYLINDER BLOCK (Typical Example)
1. 3H465 Plate. 2. 1P2396 Adapter plate. 3. Cylinder head bolt washers. 4. Spacer plate.

3. Invert 3H465 Plate (1) from an 8B7548 Push Puller, in the center of adapter plate (2). Center crossbar (6) on the inverted 3H465 Plate. Using two 3/4 in.-10 NC bolts 7 in. (177.8 mm) long and two 3H465 Plates, secure the crossbar to the cylinder block as illustrated. Tighten the bolts evenly, in four steps; 5 lb. ft. (7 N·m), 15 lb. ft. (20 N·m), 25 lb. ft. (35 N·m) and finally to 50 lb. ft. (70 N·m). Distance from bottom edge of crossbar to top plate, must be the same on both sides of cylinder liner.

4. Zero the dial indicator using the back of 1P5507 Gauge with dial indicator (5) mounted in 1P2402 Block (7).

5. Measure liner projection as close as possible to the clamping area and at four locations around the liner. The liner projection must be within .006 ± .0028 in. (0.51 ± 0.071 mm) and the four measurements should not vary more than .002 in. (0.05 mm). The average projection between adjacent cylinders for the same cylinder head must not vary more than .002 in. (0.05 mm). The difference in the average cylinder liner projection of all liners under one cylinder head must not be more than .003 in. (0.08 mm).

MEASURING LINER HEIGHT PROJECTION (Typical Example)
5. Dial indicator. 6. Crossbar. 7. 1P2402 Block.

NOTE: If liner projection varies from point to point around the liner, rotate the liner to a new position within the bore. If still not within specified limits, move liner to a different bore.

NOTE: Measure and check the following dimensions when installing new parts. With all dimensions correct, proceed with the listed Steps.

a. Spacer plate thickness, .492 ± .001 in. (12.50 ± 0.03 mm).

b. Spacer plate gasket thickness, .008 ± .001 in. (0.20 ± 0.03 mm). (All surfaces must be clean and dry when installing gasket).

c. Cylinder liner flange thickness, .5050 ± .0008 in. (12.827 ± 0.020 mm).

Liner projection can be adjusted by machining the contact face of the cylinder block with use of the 8S3140 Cylinder Block Counterboring Tool Arrangement. Form FM055228 is part of the cylinder block counterboring tool arrangement and gives tool arrangement and tool usage information.

The counterboring depth ranges from a minimum of .030 in. (0.76 mm) to a maximum of .045 in. (1.14 mm). Put a .030 in. (0.76 mm) shim directly beneath the liner flange and coat the top and bottom of the shim with 7M7260 Liquid Gasket. If more than one shim is installed put the other shims under the .030 in. (0.76 mm) shim and coat only top face of the top shim and the bottom face of the bottom shim with the 7M7260 Liquid Gasket.

Shims of various thicknesses also are available to adjust liner projection.

Cylinder Liner Projection For Engines Without Spacer Plates

1P2398 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 1P2398 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. (70 N·m). Tighten the nuts evenly in four steps; 5 lb. ft. (7 N·m), 15 lb. ft. (20 N·m), 25 lb. ft. (35 N·m), and then to 50 lb. ft. (70 N·m). 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 as illustrated, to measure liner projection. Special Instruction (GMC00623) is with the tool. Liner projection must be .004 to .008 in. (0.10 to 0.20 mm). The maximum difference in height of liners next to each other under the same cylinder head is .002 in. (0.05 mm). The maximum difference between high and low measurements made at four places around each cylinder is .002 in. (0.05 mm). Shims are available for adjustment of the liner projection. The difference in the average cylinder liner projection of all liners under one cylinder head must not be more than .003 in. (0.08 mm).

MEASURING LINER PROJECTION
1. 3H465 Plate. 2. Dial indicator. 3. 1P2402 Block. 4. Crossbar. 5. 1P2398 Puller Plate.

5. Use the 8S3140 Counterboring Tool Arrangement to bore the block deeper if needed. Bore maximum depth is .545 in. (13.84 mm).

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).

Cylinder Block

Bore in block for main bearings can be checked with main bearing caps installed without bearings. Tighten the stud nuts to torque shown in the SPECIFICATIONS. Alignment error in the bores must not be more than .003 in. (0.076 mm).

1P3537 DIAL BORE GAUGE GROUP

Special Instruction (GMG00503) gives the use of 1P4000 Line Boring Tool Group to machine main bearing bores. 1P3537 Dial Bore Gauge Group can be used to check bores. Special Instruction (GMG00981) is with the group.

Flywheel And Flywheel Housing

8S2328 Dial Indicator Group.

Flywheel Ring Gear

Heat the ring gear to a maximum of 600° F (316° C) to install. 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.

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

8S2328 DIAL INDICATOR GROUP INSTALLED

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.

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

Bore Runout (radial eccentricity) of the Flywheel Housing

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.

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

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

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

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

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

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

CHECKING BORE RUNOUT OF THE FLYWHEEL HOUSING

8S2328 DIAL INDICATOR GROUP INSTALLED

7. Add lines I & II by columns.

8. 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.

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

10. 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" do Step 11.

GRAPH FOR TOTAL ECCENTRICITY

11. Loosen the bolts holding the flywheel housing to the cylinder block. Hit the flywheel housing lightly with a hammer to put it in the correct position. Tighten the bolts holding the flywheel housing to the cylinder block and do Steps 1 through 10 again.

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 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

Bore Runout (radial eccentricity) of the Flywheel

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 .000 in. (0.0 mm).

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

CHECKING BORE RUNOUT OF THE FLYWHEEL
1. 7H1945 Holding Rod. 2. 7H1645 Holding Rod. 3. 7H1942 Indicator. 4. 7H1940 Universal Attachment.

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 FLYWHEEL CLUTCH PILOT BEARING BORE

Vibration Damper

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

If the damper is bent or damaged, or if the bolt holes in the damper are loose fitting, replace the damper. Replacement of the damper is also needed at the time of crankshaft failure (if a torsional type). See SPECIFICATIONS for eccentricity limits.

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. The wire size, color and recommendations of length are given in the WIRING DIAGRAMS in SYSTEMS OPERATION.

Battery

5P300 Electrical Tester.9S1990 or 1P7400 Battery Charger Tester.5P957 or 5P3414 Coolant and Battery Tester.

NOTE: Make reference to Special Instruction Form No. GEG02276 and to the instructions inside of the cover of the tester, when testing with the 5P300 Electrical 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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Never disconnect any charging unit circuit or battery circuit cable from battery when the charging unit is producing a charge.

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

5P300 Electrical Tester.

NOTE: Make reference to Special Instruction (GEG02276) and to the instructions inside of the cover of the tester, when testing with the 5P300 Electrical Tester.

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. Wires, 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

When an alternator is charging the battery too much or not enough, an adjustment can be made to the charging rate of the alternator. Remove the hollow head screw (1) from the cover of the alternator regulator and use a screwdriver to turn the adjustment screw. Turn the adjustment screw one or two notches to increase or decrease the charging rate of the alternator.

LOCATION OF ADJUSTMENT SCREW FOR THE 6L5397 and 6L3432 ALTERNATOR REGULATORS
1. Hollow head screw. 2. Connector.

Starting System

5P300 Electrical Tester.

NOTE: Make reference to Special Instruction (GEG02276) and to the instructions inside of the cover of the tester, when testing with the 5P300 Electrical Tester.

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. Ground the other lead. 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 the need for repair to the solenoid or an adjustment to be made to starter pinion clearance. Pinion clearance is .36 in. (9.14 mm).

If the solenoid for the starting motor will not operate, current from the battery may not be getting to the solenoid. Fasten one lead of the voltmeter to the connection (terminal) for the battery cable on the solenoid. Ground the other lead. 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 connector (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 ground the other lead. 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 Clerance 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).

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 commutator end to remove free movement.

6. Pinion clearance (6) must be .36 in. (9.14 mm).

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

Rack Shutoff Solenoid

The plunger shaft and linkage initial adjustment of distance from mounting face to linkage hole center should be 3.875 in. (98.43 mm).

Travel can be measured with rack gauges to be sure rack is moved to off position. Make an engine check with a 30A ammeter to be sure only the hold in windings are energized when the rack is held by the solenoid in off position. Current draw (consumption) must be less than 2A.

PLUNGER SHAFT ADJUSTMENT
1. Distance from mounting face to link hole center when plunger face is 3.875 in. (98.43 mm) from mounting face. 2. Effective travel .5 in. (12.7 mm). 3. Starting position of plunger from mounting flange is .75 in. (19.1 mm) to measure effective travel of plunger.

The adjustment of the linkage is done with pin (4) removed and the governor linkage disconnected.

1. Move the rack toward the front of the engine to the full closed position.

2. Activate the solenoid (5) and hold it there.

RACK SHUTOFF SOLENOID LINKAGE
4. Pin. 5. Solenoid. 6. Lock nut.

3. Install the pin (4). If the pin holes will not align, loosen the lock nut (6) and decrease or increase the length of the linkage so the pin can be installed.

4. Stop activating the solenoid.

5. Connect the governor linkage.

6. Check the adjustment to be sure the amperage draw (consumption) is less than 2A when the solenoid and rack are in fuel closed position.

7. With the solenoid not activated, check to be sure the rack moves freely. Install the governor linkage and covers.