G333C ENGINE Caterpillar

Testing And Adjusting


Problem Solving


1. Engine Fails to Start
2. Misfiring
3. Stalls at Low Speed
4. Erratic Engine Operation
5. Lack of Power
6. Excessive Vibration
7. Valve Train Clicking Noise
8. Oil in Coolant
9. Mechanical Knock
10. Excessive Gas Consumption
11. Loud Valve Train Noise
12. Little Rocker Arm Movement and Excessive Valve Lash
13. Valve Rotocoil or Spring Retainer Free
14. Slobber
15. Valve Lash Close-up
16. Premature Engine Wear
17. Coolant in Engine Lubricating Oil
18. Low Engine Oil Pressure
19. High Lubricating Oil Consumption
20. Abnormal Engine Coolant Temperature
21. Starting Motor Fails to Crank
22. Alternator or Generator Fails to Charge
23. Alternator or Generator Charging Rate Low or unsteady.
24. Alternator or Generator Charging Rate Excessive
25. Noisy Alternator or Generator
26. Short Spark Plug Life
27. Pre-Ignition
28. Surging
29. Detonation
30. Gas Supply Line Solenoid Valve Fails to Close
31. Instrument Panel Gauge Switches Fail to Stop Engine
32. Instrument Panel Gauge Switches Prevent Engine Start
33. Overspeed Contactor Switch Fails to Signal Shutoff
34. Overspeed Contactor Switch Signals Shutoff at Low Speed

Gas, Air Induction And Exhaust Systems

Restriction Of Air Inlet And Exhaust

Engine horsepower and efficiency will be reduced if either the air inlet or exhaust system becomes restricted.

The air cleaner should not restrict air flow more than 30 in. (762 mm) of water difference in pressure.

Exhaust back pressure (pressure difference measured between the turbocharger outlet elbow tap and ambient air) should be no more than 15 in. (381 mm) of water. Back pressure for naturally aspirated engines, should be 25 in. (635 mm) of water, measured between exhaust outlet and ambient air.

Crankcase Pressure

Crankcase pressure (difference from ambient) above 3 in. (76,2 mm) of water is excessive and can be a result of combustion gas leaking past broken or damaged pistons and/or piston rings. This condition will usually be accompanied by irregular engine operation and excess fumes from crankcase breather opening. This condition can cause the breather element to become restricted in an unusually short time. In addition, excessive pressure can cause engine oil to leak past gaskets and seals that would function properly under normal conditions.


Irregular (rough) engine operation can be caused by improperly adjusted or leaky valves. Operate the engine at RPM which makes the malfunction most pronounced. A non-firing or low compression cylinder can be located by removing spark plug wires one at a time. Continue this until a removed wire makes little or no difference in the engine operation. This same test can also indicate faulty spark plugs so further checking of the cylinder is necessary.

The preceding test is merely a quick means of pinpointing the source of cylinder compression loss. Removal of the head and visual inspection of the valves and seats is necessary to check for minor valve defects which do not have much effect on engine operation. This is usually done during general engine reconditioning.

The following procedure provides a more complete check of the sealing ability of the individual valves without removing the cylinder head:

1. Remove the spark plug, leaving the spark plug adapter in place.

2. Adapt an air hose to the spark plug adapter. This can be done with either a threaded fitting or by holding a rubber adapter in place.

3. Rotate the crankshaft until the piston in the suspected cylinder is at top center (TC) on the compression stroke. In this position the valves of the cylinder are closed.

4. Force air into the cylinder and then check for escaping air. Air escaping from the exhaust opening indicates exhaust valve leakage. Air escaping from the air cleaner inlet indicates inlet valve leakage. If air escapes from the crankcase breather during this test, the piston, rings and/or liner can be at fault.

On turbocharged engines, it may be necessary to remove inlet and outlet connections on both sides of turbocharger to notice leakage.

Performance Evaluation Turbocharged Engines

When an engine is suspected of lacking power, it is sometimes desirable to make a quick instrument check to determine the approximate horsepower.

The 4S6553 Instrument Group provides a means to make this quick check. This group contains an instantaneous reading tachometer and a gauge for reading inlet manifold pressure. Instructions (FE04044) included with this group, explain the testing procedure.

1-Lid. 2-4S6997 Manifold Pressure Gauge. 3- Pressure tap fitting. 4-4S6992 Differential Pressure Gauges. 5-4S6991 Tachometer. 6-Zero adjustment screws. 7-8M2743 Gauge.

Satisfactory evaluation from the instruments and test procedure is dependent upon the engine operating adjustments being correct.

By checking inlet manifold pressure, and comparing that pressure with the RACK SETTING INFORMATION, determination can be made if an engine is operating efficiently. This test should be used if engine horsepower seems to be too low, yet no specific symptom of engine trouble is apparent.

Line Pressure Regulator

A line pressure regulator is required if the engine is turbocharged, or if the fuel supply pressure is exceptionally high.

CHECKING LINE PRESSURE REGULATOR ADJUSTMENT (Schematic Diagram for Turbocharged Engine)
A-Positive pressure differential. 1-Bottom port. 2- Adjustment screw. 3-Gas supply at carburetor. 4- Water manometer. 5-Valve.

1. Line pressure regulator adjustment can be checked with either the 4S6553 Instrument Group or a water manometer while engine is running.

2. Attach one end of a water manometer (4) to the gas supply at carburetor (3). On turbocharged engines, attach the other end of the manometer to the bottom port (1) of the line pressure regulator as shown, to measure the pressure differential (A). On naturally aspirated engines, attach the manometer only at (3) and leave the other end open to the atmosphere.

3. Remove the cap and turn screw (2) until the value (A) is within the specified range. Natural Gas: 51/2 in. (139,7 mm); Propane: 1 in. negative (25,4 mm).

NOTE: The valve (5) should be closed before the engine is stopped. This will prevent the manometer fluid from being drawn into the inlet of the carburetor (3).

Cylinder Head

Tools required to remove valve seat inserts are in the 9S3080 Valve Insert Puller Group.

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

Tools required to install valve guides are: 7S8858 Driver Bushing and 7S8859 Driver. The counterbore in the driver bushing mates with the counterbore in the cylinder head to limit driving the guide.

Use an 8S7227 Wrench to remove and install the spark plug adapters. Coat bore in head and seal with liquid soap. Coat threads with 9M3710 Anti-Seize Compound.

Valve Clearance Setting


Carburetor and governor linkage adjustments are covered in the topic GOVERNOR.

Turn power mixture adjustment (2) to center between "R" (rich) and "L" (lean). Make fuel mixture adjustments by changing the gas pressure from the line pressure regulator.

1-Throttle stop screw. 2-Power mixture adjustment. 3 -Idle adjustment screw.

Turn idle adjustment screw (3) four full turns open (from the closed position).

Turn throttle stop screw (1) to obtain desired idle speed. The recommended low idle is 590-610 RPM (1200-1250 RPM when used with electric sets).

Differential Pressure Regulator

The regulator has two .25 in. (6,4 mm) spacers (3) for altitude adjustment. Both spacers should be used for operation up to 1500 feet (457,2 m) altitude. Remove one for operating between 1500 and 4000 feet (457,2-1219,2 m). A slight amount of adjustment can be made by adding or removing shims (9). The regulator assembly bolts should be sealed at assembly.

1-Measurements for testing regulator. 2-Pressure sensing port connection. 3-Spacers. 4-Bypass valve. 5-Breather location. 6-Bypass passage. 7 -Turbine housing. 8-Diaphragm. 9-Shims.

To test the regulator with both spacers (3) in place, and atmospheric pressure in spring compartment, apply 6.65-7.20 (0,47-0,51 kg/cm2) to pressure chamber through connection (2). Measurement at (1) should be 2.893 in. (73.48 mm).

NOTE: Information in Form FE034610 shows equipment for testing and adjusting this regulator.



Only competent personnel should attempt to adjust the low and high idle RPM. The low and high idle RPM settings for this engine are listed in the RACK SETTING INFORMATION.

Engine RPM should be checked with a 9M478 tachometer. Be sure the linkage is adjusted correctly before making any governor adjustments.

Linkage Adjustment

1. Clamp the carburetor lever (1) on the carburetor throttle shaft at angle indicated when the throttle plate is closed.

2. Drill 1/8 in. thru shaft and lever and pin to shaft.

3. Adjust the length of linkage rod (3) so the angles at carburetor lever (1) and governor lever (2) are maintained.

NOTE: Governor lever in shutoff position and throttle plate closed.

LINKAGE ADJUSTMENT (Later Type) Dimensions in inches (mm)
1-Carburetor lever. 2-Governor lever. 3-Linkage rod.

LINKAGE ADJUSTMENT (Earlier Type) Dimensions in inches (mm)
1-Carburetor lever. 2-Governor lever. 3-Linkage rod.

High Idle Adjustment

9M478 Tachometer

High idle RPM can be adjusted by removing the governor rear cover (1), and turning the high idle adjusting screw (2). Turning adjusting screw in a clockwise direction will decrease the idle RPM. The retainer hole in the cover is shaped to prevent the screw from turning, after the adjustment has been made.

1-High idle adjusting screw. 2-Cover.

After setting the idle RPM, move the governor control lever to change the engine RPM. Return it to the idle position and recheck the idle RPM. Repeat the adjustment procedure until the specified idle RPM is obtained.

Low idle speed adjustment is made at the carburetor.

Cooling System

The engine has a pressurized cooling system. Pressurizing the cooling system serves two purposes. First, it permits safe operation at coolant temperature higher than the normal boiling point; thereby, providing a margin of cooling for those intermittent peak loads. Secondly, it prevents cavitation in the water pump and reduces the possibility of air or steam pockets forming in the coolant passages.

Many times, overheating of the engine is caused by failure to make simple systematic inspections. Visual inspections should be made before instrumentation testing.

Visual Inspection

1. Check coolant level.

2. Inspect for leaks in the system.

3. Inspect the radiator fins. Be certain the air flow through the radiator is not restricted by trash or bent radiator fins.

4. Check fan belts.

5. Check for damaged fan blades.

6. Observe if there is any air or combustion gas in the cooling system.

7. Check to see that the expansion tank, heat exchanger or radiator cap sealing surfaces are clean.

Testing Cooling System

Remember that temperature and pressure go hand-in-hand and neither one can be tested logically without considering the other. For example, the effect of pressurization and altitude on the boiling point of water is shown in the chart.

Temperature Gauge

2F7112 Thermometer6B5072 Bushing.

If overheating and loss of coolant is a problem, a pressure loss in the system could be the cause. If an overheating condition is indicated on the temperature gauge and loss of coolant is not evident, check the accuracy of the temperature gauge. Make this check by installing a 2F7112 Thermometer (using a 6B5072 Bushing) into the cylinder head.

Use CAUTION when working around an engine if it is running.

Start the engine. Partially cover the radiator or reduce flow of raw water to reduce cooling. The instrument panel temperature gauge contacts should be adjusted so the indicator just touches the contact at 210°F (99°C).

1-Adjustment screw.

Pressure Cap

If the pressure check indicates that the system is unable to hold pressure, the source of the pressure leak must be determined. One of the causes of cooling system pressure loss can be a faulty pressure cap seal. Inspect the pressure cap carefully for possible damage to the seal or sealing surfaces. The build-up of deposits on the cap, seal and filler neck should be removed.

Water Temperature Regulator

The opening temperature of the regulator (bench test in atmospheric pressure) is approximately 165° ± 1°F (74° ± 1°C). The regulator should be fully open at approximately 180°F (82°C).

Ignition System

Test the magneto, by the intensity of the spark at the spark plug. When testing, remember that the magneto output is effected by the condition of the instrument panel components-magnetic switch, stop switch, oil pressure gauge and water temperature gauge. An overspeed shutoff contactor, and/or gas line solenoid valve connected with the magneto could cause an indication of magneto malfunction.

Timing Magneto To Engine

1. Remove the timing pointer cover from the flywheel housing

2. Rotate crankshaft in direction of engine rotation until No. 1 piston is coming up on compression stroke.

3. Continue rotating crankshaft until desired timing mark appears directly under flywheel pointer. See Chart of Instructions for Timing Magneto for various conditions such as gas used and compression ratio.

NOTE: After top center (ATC) timing, with engine stopped, is required under some conditions. When earlier flywheels without ATC calibrations are encountered, mark the flywheel .805 in. (20.45 mm) on outside diameter of flywheel for each 5°.

FLYWHEEL TIMING MARKS (Viewed from left side of engine)
1-Flywheel pointer. 2-Calibrations after top center (ATC). 3-Calibrations before top center (BTC).

4. Position the magneto drive slots in proper position for timing. The drive coupling can be pulled to rear, then positioned and pushed forward into engagement.

5. With magneto off the engine, remove timing bolt and rotate magneto drive until timing mark (4) is in center of opening.

DRIVE TANG AND DRIVE SLOT POSITIONS (Viewed from the rear of the engine)

6. Install the magneto. The drive tang and slot should engage.

4-Timing mark.

7. Make final timing adjustment by rotating the magneto at the drive housing mounting and with the use of a timing light when the engine is running. When properly timed, the mark on flywheel will align with pointer as timing light flashes.

Magneto Point Gap

Magneto point gap should be set at .017 in. (0,43 mm).

Firing Order

The firing order is 1-5-3-6-2-4. The direction arrows in the illustration indicate rotation of the magneto distributor disc and drive tang (A) as viewed from the end cap cover (rear of engine).

A-Drive tang.

Magneto Edge Gap

Maximum ignition discharge is obtained by interrupting the primary circuit at the instant the primary circuit reaches its maximum value. At this point, the contact points should just be beginning to open.

Field Method

When a setting of edge gap is required to be made in the field without the use of a synchroscope, a temporary setting can be made. This edge gap is set by locking a 1/8 in. (3,175 mm) rod between the rotor pole shoe and the housing field.

1. Check contact points and adjust to proper gap.

2. Remove impulse coupling.

3. Turn the rotor shaft so the keyway is up, then turn the shaft approximately 15° in direction of magneto rotation.

4. View magneto from drive end. Remove set-screw and insert 1/8 in. (3,175 mm) rod (4) in timing hole (3). Use left hole for counterclockwise rotation magnetos. Illustration shows rod (4) inserted in proper hole for clockwise rotation magneto.

5. Loose support plate screws (1).

EDGE GAP ADJUSTMENT (Clockwise Magneto)
A-15° angle.

6. Press rod (4) inward until it contacts rotor. Turn rotor shaft in direction opposite normal rotation until rod locks tight between the rotor pole shoe and housing field.

EDGE GAP ADJUSTMENT (Clockwise Magneto)
1-Support plate screws. 2-Support plate. 3-Timing holes. 4-Rod.

7. With rotor in this position, move plate (2) either left or right until contact points start to open. Tighten support plate screws (1) securely.

NOTE: The point of initial contact point opening can be determined by inserting a thin piece of cellophane between the points, using a timing light, or a sounding device.

8. Install impulse coupling.

Synchroscope (Shop) Method

The most accurate method of setting the edge gap is with a synchroscope.

1. Select a coupling that adapts to the tapered and keyed magneto drive shaft and mount the magneto on the synchroscope.

2. Rotate degree disc (1) until 0° is in alignment with pointer (2).

3. Connect a wire (8) between the contact point terminal and a primary terminal of transformer (5).

4. Connect a wire (7) between the other primary terminal on the transformer and the magneto housing (4).

5. Run a high tension wire (3) from the secondary outlet of the transformer to the degree disc on the synchroscope.

1-Degree disc. 2-Pointer. 3-Wire. 4-Magneto housing. 5-Transformer. 6-Wire to contact point. 7-Wire to housing.

6. Drive the magneto in the direction of normal rotation at 1800 RPM.

7. Adjust the edge gap (contact point opening timing) by rotating the contact point support plate (8) until the spark jumps from the degree disc to the rotating pointer at 15° after 0° in the direction of rotation.

8. Tighten the support plate.

8-Support plate.

Brush Spring Adjustment

The distance between distributor block (3) and face of distributor disc (5) should be checked each time the magneto is serviced. The proper separation provides for correct pressure on brush and spring assembly (6). To check remove timing window capscrew and insert drill rod (4) between block (3) and disc (5). The minimum clearance is 5/32-7/32in. (3,97-5,56 mm).

To increase clearance insert an additional end cap cover gasket (2). To decrease clearance use #10 washers between distributor block (3) and end cap cover (1).

1-End cap cover. 2-End cap cover gasket. 3-Distributor block. 4-Drill rod. 5-Distributor disc. 6-Brush and spring assembly.

Starting And Charging Systems

Most of the electrical system testing can be performed on the engine. The wiring insulation must be in satisfactory condition, the wire and cable connections both clean and tight and the battery fully charged. An "on-engine" test that indicates a defective component usually requires component removal for further testing.

The wire size, color and recommended length is provided in the topic WIRING DIAGRAM.



The storage battery circuit represents a continuous, although variable, electrical load to the alternator. If the circuit, positive or negative is opened or broken while the alternator is charging, the loss of the battery load will result in the charging voltage rising to unsafe levels.

High voltage will damage the alternator and regulator and may damage other electrical components or instruments.


A load test should be made on a battery that discharges very rapidly when in use. To do this apply a resistance of (for 6 volt-two times and for 12 volt-three times) the ampere/hour rating of the battery across the battery main terminals. Allow the resistance to discharge the battery for 15 seconds and 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 instructions included with the 9S1990 Battery Charger Tester covers completely the battery testing subject.

Charging System

The condition and state of charge of the battery at each regular inspection will indicate if the charging system is operating efficiently. An adjustment is necessary when the battery is always in a low state of charge or an excessive amount of water must be added to the battery (more than one ounce of water per cell per week or per every 50 service hours).

Alternators and voltage regulators should be tested on the engine when possible, using wiring and accessories that are a permanent part of the system. Bench testing will provide the technician with an operational test of the alternator or voltage regulator. Pre-repair testing will advise the depth of needed repairs. Final testing will prove the units are restored to their original operating efficiency.

Before starting the on-engine test the charging system and battery must be checked as stated in the following steps to eliminate possible difficulty.

1 Battery must be at least 75% (1.240 Sp. Gr.) full charged and properly secured in the carrier. The carrier must not place excessive physical strain on the battery.

2 Cables between the battery, starter and engine ground must be of recommended wire size. Wires and cables must be free of corrosion with cable supporting clamps to reduce strain on battery posts.

3 Leads, junctions, switches and panel instruments that are directly related to the charging circuit must be good enough to provide proper circuit control.

4 Inspect the alternator drive, crankshaft pulley, alternator pulleys and drive belts to be sure they are free of grease and oil and are capable of driving the charging unit load.

Voltage Regulator Adjustment

Test equipment required: Volt-Ammeter that will provide (D.C. Volts 0-16 Volts) (D.C. Ammeter 0-10 amps and 0-100 amps.)

Before making adjustments, consider the condition of the battery. See the topic BATTERY.

Step Adjustment

To raise the voltage (approximately .4 volt on 12 volt system) remove locknuts from the two terminals closest to the word "HI". Place metal strap over these studs, replace nuts and tighten securely.

To lower voltage (.4 volt on 12 volt system) install strap over studs closest to word "LO". Refer to SPECIFICATIONS for setting range.


Fine Adjustment

A fine adjustment can be made when the alternator and regulator are warm and after the step adjustment is made. Refer to SPECIFICATIONS for voltage regulator setting range.

1. With engine stopped, connect a voltmeter to the battery and an ammeter in series with the output of alternator.

2. Start engine and run it at about half engine speed and apply load so that the ammeter in Step 1 reads 10 to 15 amps.

3. Run engine 5 to 15 minutes. The voltmeter should give a stable reading after this period of warm up.

1-Cover screw.

4. Remove cover screw (1) from insulator and use a #0 Phillips screwdriver to adjust. Turn clockwise to raise voltage.

NOTE: Stops limit adjustment to 1/2 turn total.


Do not allow screwdriver to touch anything but voltage adjusting screw.

Alternator (Motorola)

1/4 Test equipment required: Volt-Ammeter that will provide: (D.C. Volts 0-16 volts) (D.C. Ammeter 0-10 amps and 0-100 amps), a Field Rheostat-0.50 ohms resistance, 50 watts, a Fixed Resistor ohm, a Carbon Pile, a Test lamp, battery operated and an Ohmmeter.


Before making adjustments, consider the battery condition. See the topic BATTERY.

Battery Circuit Test

Condition: Engine not running; oil pressure switch open.

1. Connect test ammeter between alternator POSITIVE OUTPUT terminal and battery positive terminal.

NOTE: test ammeter remains in the same position throughout all the tests.

2. Connect voltmeter positive lead to battery positive terminal, negative lead to battery negative terminal. Read voltages. Correct voltage on 12 volt system should be 11.9 to 12.6 volts.

3. Move voltmeter positive lead to battery side of oil pressure switch. Leave negative lead on battery negative terminal. Read voltage. Then move positive lead to alternator POSITIVE OUTPUT terminal. Read voltage. Voltages should read the same as in step 2. If voltage is lower, check and repair cables, leads or terminals as required.

4. Ammeter should read zero at all times during these tests. If ammeter reads down scale, it indicates a shorted diode in the alternator.

Control Switch Positive Diode Test

Condition: Engine not running. Oil pressure switch open.

1. Connect positive lead of voltmeter to alternator TACHOMETER terminal, negative lead to battery negative terminal. Voltmeter should read zero. If voltmeter reads above zero, one or more of the positive rectifier diodes in alternator is shorted.

2. Connect voltmeter positive lead to alternator side of oil pressure switch, negative lead to battery negative terminal. Voltmeter should read zero. If voltmeter reads above zero, oil pressure switch may be shorted.

3. Test ammeter should show zero throughout these tests.

Rotor (Field) Current Draw Test

Condition: Engine not running, oil pressure switch open.

This test requires temporary addition of test carbon pile to battery to reduce voltage to reference level and a field rheostat.

1. Turn load control knob of carbon pile to OFF position and connect leads to battery.

2. Remove lead from #1 FIELD terminal of alternator.

3. Place field rheostat knob in maximum resistance position; connect leads to #1 FIELD terminal and POSITIVE OUTPUT terminal of alternator.

4. Connect test voltmeter negative lead to NEGATIVE OUTPUT terminal of alternator, positive lead to #1 FIELD terminal.

5. Read all test instruments. Carbon pile voltmeter should read battery voltage. Ammeter should read zero amps. Test voltmeter and test ammeter may indicate near zero depending on resistance value of field rheostat.

6. Slowly decrease resistance of rheostat to zero. Test voltmeter will indicate battery voltage. Ammeter will indicate current draw of rotor (field winding). If ammeter reads excessive current (more than 5 amps) reverse rheostat to maximum resistance. This indicates a short. Disconnect leads and inspect brushes and rotor circuit for cause of high current draw.

7. Slowly apply carbon pile load to battery until test voltmeter reaches reference point shown in table. Check test ammeter for rotor (field) current draw; it should be within limits down in table.

8. If field current draw falls within the limits shown, rotor winding is good. If field current exceeds the maximum, alternator should be bench tested. Check for defective or dislocated brushes, shorted brush leads, foreign material between slip rings or shorted rotor (field) winding.

9. Turn carbon pile load off immediately after test to avoid discharging battery.

Regulator Load Circuit Loss Test

Condition: Engine not running. Oil pressure switch bypassed with jumper cable.

1. Connect negative lead of test voltmeter to alternator NEGATIVE OUTPUT terminal, positive lead to #1 FIELD terminal. Voltmeter should read .9 to 1.5 volts less than battery voltage for all systems. This is the maximum allowable voltage drop through the voltage regulator. A reading lower than .9 volts or higher than 1.5 volts indicates a defective voltage regulator.

2. Remove jumper wire from oil pressure switch after completion of test.

Current Output Test

Condition: Engine not running. Oil pressure switch open.

1. Connect voltmeter and ammeter leads from carbon pile to battery terminals.

2. Turn load control knob to OFF.

3. Connect test voltmeter and ammeter. Voltmeter should read battery; ammeter should read zero amps.

4. Start engine (oil pressure switch will activate alternator) and run for 5 minutes to stabilize alternator unit temperature.

5. Slowly increase load with carbon pile and increase engine speed until minimum rated current output is reached.

6. Check voltage on test voltmeter.

7. If volts exceed maximum limit, check or replace voltage regulator. If system operates normally at low speeds but cannot obtain minimum rated current output at high engine speeds, check fan belt for proper tension.

8. Disconnect carbon pile load immediately after alternator is stopped to avoid discharging battery.

Starting System

Use a D.C. voltmeter to locate starting system components which do not function.

Move starting control switch to energize the starter solenoid. Starter solenoid operation is audible as the starter motor pinion engages with the ring gear on the engine flywheel. The solenoid operation should also close the electric circuit to the motor. Attach one voltmeter lead to the solenoid terminal that is connected to the motor. Ground the other lead. Energize the starter solenoid and observe the voltmeter. A battery voltage reading indicates the malfunction is in the motor. It must be removed for further testing. No voltmeter reading indicates that the solenoid contacts do not close and the solenoid must be repaired or the starter pinion clearance should be adjusted to .36 in. (9,14 mm).

A starting motor solenoid that will not operate may not be receiving battery current. Attach one lead of the voltmeter to the solenoid battery cable connection. Ground the other lead. No voltmeter reading indicates a faulty circuit from the battery. A voltmeter reading indicates further testing is necessary.

Continue the test by attaching one voltmeter lead to the starting motor solenoid small wire terminal and the other lead to ground. Observe the voltmeter and energize the starter solenoid. A voltmeter reading indicates that the malfunction is in the solenoid. No voltmeter reading indicates the starter switch or wiring is the fault.

Attach one lead of the voltmeter to the starter switch battery wire terminal and ground the other lead. A voltmeter reading indicates a defective switch.

A starting motor that operates too slow can be overloaded by excessive mechanical friction within the engine being started. Slow starting motor operation can also be caused by shorts, loose connections and/or excessive dirt within the motor.

Pinion Clearance Adjustment (Delco-Remy)

Whenever the solenoid is installed, the pinion clearance should be adjusted. The adjustment should be made with the starting motor removed.

Specific points related to the circuit connections for checking pinion clearance are: 1-Connector from motor terminal on solenoid to motor. 2-SW terminal. 3-Ground terminal.

Bench test and adjust the pinion clearance at installation of solenoid as follows:

1. Install the solenoid without connector from the MOTOR terminal on solenoid to the motor.

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

3. Connect the other side of battery to ground terminal or to solenoid frame.

This schematic shows the circuit for checking and adjusting pinion clearance. 2-SW t terminal. 3-Ground. 4-Ground flashing point.

4. MOMENTARILY flash a jumper wire from the solenoid terminal marked MOTOR to the frame or ground terminal. The pinion will shift into cranking position and will remain there until the battery is disconnected.

5. Push pinion towards commutator end to eliminate free movement.

6. Pinion clearance should be .36 in. (9,14 mm).

7. Adjust clearance by removing plug and turning shaft nut.

This illustrates the points where pinion clearance checking and adjusting are made. 5-Pinion. 6-Pinion clearance. 7-Shaft nut.

Basic Block

Cylinder Liner Projection

Install seals on the liner. Coat seals and mating bore with liquid soap before installing liner. Position liner in bore chamfer. Place a 8S3611 Adapter Plate on top of liner. Use a block of hard wood over adapter and drive liner into place. Use the crossbar from the 8B7548 Push Puller. Clamp the liner down with two 5/8" - 18 NC bolts 41/2 in. 114,30 mm) and flat washers. Tighten the bolts to 50 lb. ft. (6,9 mkg). Use a depth micrometer as illustrated to measure liner projection. Measure down from the liner surface contacting the head gasket to the face of the cylinder block. Liner projection must be .002-.0056 in. (0,05-0,142 mm).


Connecting Rods And Pistons

Use 7S9470 Piston Ring Expander to remove or install piston rings.

Use 9S9417 Piston Ring Compressor to install pistons into cylinder block.

Tighten connecting rod bolt nuts in the following Step sequence:


Heat crankshaft gear to 600°F. (315°C.) maximum before installing on crankshaft. Install seal so spring-loaded lip faces centerline of cylinder block.

Viscous Type Vibration Damper

The viscous type vibration damper can be tested to determine if it is functioning properly. When the engine speed is reduced gradually from high idle to 2/3 of high idle, the timing gear train noise may be more noticeable at some speed within this range if the damper is faulty.

The following test will indicate the condition of the damper.

1. Attach hooks (1) in the mounting bolt holes. Clamp round rod (4) to the damper machined side and tighten nuts (6) to prevent shifting in handling.

NOTE: Use care in handling to avoid changing the rod location in respect to the original mounting on the damper.

2. Support damper (2) between angle irons (5) on blocks (8). Angle iron edges and rod should have smooth contact areas.

3. Place washers (3) on the light side to balance level (7). Record the number of washers.

4. Stand damper on edge for 8 to 24 hours so the internal solid cast iron core can settle to the low side. Mark 6 o'clock (bottom) and 12 o'clock (top) locations on the damper.

5. Repeat Steps 2 and 3.

1-Hook. 2-Damper. 3-Washers. 4-Round rod. 5-Angle irons. 6-Flat washers and nuts. 7-Level. 8-Blocks.

6. Stand damper on edge at 12 o'clock mark for 8 to 24 hours.

7. Repeat Steps 2 and 3.

8. If balance washers have to be shifted between 6 to 12 o'clock locations in Step 3, the damper is in good condition. If the washers are continuously required at the same location, either 6 o'clock or 12 o'clock, it indicates the damper needs replacing because the iron core is not free to move but has become "locked up".

Flywheel And Flywheel Housing

Heat ring gear to install. Do not exceed 600°F. (315°C.). Install ring gear so chamfered portion of gear teeth face the starter pinion when flywheel is installed.

Checking Flywheel Housing Face Runout

Make tool setup from parts of 8S2328 Dial Test Indicator Group.

A-Bottom. B-Right side. C-Top. D-Left side.

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

2. Pry the crankshaft to rear before taking readings at each point.

3. With dial indicator set at .000 in (0,0 mm) at point (A), rotate crankshaft and take readings at points (B), (C) and (D).

4. The difference between the lowest and highest readings taken at all four points should not exceed .008 in. (0,203 mm), which is the maximum permissible flywheel housing face runout.

Checking Flywheel Housing Bore Runout

Make tool setup from parts of 8S2328 Dial Test Indicator Group.

1. Fasten the dial indicator to the crankshaft flange and adjust it to read .000 in. (0,0 mm) when the anvil is touching bore at point (1).

2. Pry the crankshaft in such a manner to remove crankshaft main bearing clearance when taking readings at each point.

3. Rotate crankshaft and take readings at points (2), (3) and (4).

4. The difference between the lowest and highest readings taken at all four points should not exceed .008 in. (0,203 mm), which is the maximum permissible flywheel housing bore runout.

1-Bottom. 2-Right side. 3-Top. 4-Left side.

NOTE: If any method other than described here is used, always consider bearing clearances to obtain correct readings.

Checking Flywheel Face Runout

Make tool setup from parts of 8S2328 Dial Test Indicator Group.

1. Mount a dial indicator as shown and pry the crankshaft in the same direction before taking all readings so the end clearance is always in the same direction.

2. Set the dial indicator (3) to read .000 in. (0,0 mm).

3. Turn the flywheel and take readings every 90°.

4. The difference between the lowest and highest readings taken at all four points should not exceed .006 in. (0,152 mm), which is the maximum permissible flywheel face runout.

1-8S2329 Base and 8S2327 Post. 2-7H1945 Holding Rod. 3-7H1942 Indicator.

Checking Flywheel Bore Runout

Make tool setup from parts of 8S2328 Dial Test Indicator Group.

1-7H1945 Holding Rod. 2-8S2329 Base and 8S2327 Post. 3-7H1940 Universal Attachment. 4-7H1942 Indicator.

1. Mount the dial indicator (4) and adjust it so the universal attachment (3) contacts the flywheel bore as shown.

2. Adjust the dial indicator to read .000 in. (0,0 mm) then take readings every 90° around the flywheel.

3. The difference between the lowest and highest readings taken at all four points should not exceed .006 in. (0,152 mm), which is the maximum permissible flywheel bore runout. Flywheel clutch pilot bearing bore run out should not exceed .005 in. (0,127 mm).

1-7H1945 Holding Rod (7H1654 Holding Rod in addition for aluminum or large diameter housings). 2-8S2329 Base and 8S2327 Post. 3-7H1940 Universal Attachment. 4-7H1942 Indicator.

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