3306C Truck Engine Caterpillar

Checking Engine Timing with 8T-5300 Engine Timing Indicator Group and 8T-5301 Diesel Engine Timing Adapter Group

Illustration 1	g00319643
8T-5300 Engine Timing Indicator Group (1) 8T-5250 Engine Timing Indicator (2) 5P-7366 Cable Assembly (3) 6V-2197 Magnetic Transducer (4) 5P-7362 Cable (5) 6V-2199 Transducer Adapter and 6V-3093 Transducer Adapter (6) 8K-4644 Fuse

The 8T-5300 Engine Timing Indicator Group must be used with the 8T-5301 Diesel Engine Timing Adapter Group.

Illustration 2	g00319663
8T-5301 Diesel Engine Timing Adapter Group (7) 5P-7437 Adapter (8) 6V-2198 Cable (9) 5P-7436 Adapter (10) 6V-7910 Transducer (11) 5P-7435 Tee Adapter (12) 6V-3016 Bolt

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A high pressure fuel line must be disconnected. To avoid personal injury or fire from fuel spray, the engine must be stopped before the fuel line is disconnected.

When you check for the dynamic timing on an engine without a mechanical advance, Caterpillar Inc. recommends the recording of the calculations for the dynamic timing onto paper. Then, the service person can create a graph of the dynamic advance.

Note: Order one Special Instruction, SEHS8140. Worksheets are available in pads of fifty. See Special Instruction, SEHS8580 for information on calculating the timing curve.

Note: For all engines that are regulated for emission control, use the dynamic timing at 1000 rpm to measure the static fuel injection timing. Also, use the dynamic timing at 1000 rpm to set the static fuel injection timing. Do not use pin timing for this measurement or for this setting.

After the timing values are calculated and the timing values are plotted, the dynamic timing should be checked with the 8T-5300 Engine Timing Indicator Group. Follow these steps:

1. Operate the engine from 1000 rpm (base rpm) to high idle.

2. Continue running the engine now from high idle to 1000 rpm (base rpm).

   Unstable readings often appear below 1000 rpm.

3. Record the dynamic timing at each 100 rpm and at the specified speeds during acceleration and during deceleration.

4. Finally, plot the results onto the worksheet. Review the plotted values.

Use Special Instruction, SEHS8580 to see the correct specifications for calculating the timing curve.

You can find these specifications in three places:

• The Operating Instructions inside the lid of the 8T-5300 Engine Timing Indicator Group

• The Special Instruction, SEHS8580

• The Engine Information Plate for the performance specification number

The performance specification number can be used to refer to the TMI. Here, you will find the correct timing specifications to use.

Procedure for Timing Check

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A high pressure fuel line must be disconnected. To avoid personal injury or fire from fuel spray, the engine must be stopped before the fuel line is disconnected.

Illustration 3	g00319821
Transducer in Position (10) Injection transducer. (13) Fuel injection line for No. 1 cylinder.

1. Loosen all fuel injection line clamps that hold No. 1 fuel injection line. Disconnect fuel injection line (13) at the fuel injection pump.

2. Slide the nut upward and move out of the way. Attach the 5P-7436 Adapter (9).

3. Tighten 5P-7436 Adapter (9) onto the pump bonnet. Turn adapter (9) onto the pump bonnet. Continue until the top of the bonnet's threads lines up with the bottom of the opening in adapter (9) .

4. Attach 5P-7435 Tee Adapter (11) onto injection transducer (10). Then, connect 5P-7435 Tee Adapter (11) in the opening of 5P-7436 Adapter (9) .

5. Place fuel injection line (13) on top of 5P-7435 Tee Adapter (11). Install 5P-7437 Adapter (7). Tighten the adapter (7) to a torque of no more than 40 N·m (30 lb ft).

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Illustration 4	g00319823
Transducer in Position (3) Top center magnetic transducer. (5) Transducer adapter.

6. Remove the plug from the flywheel housing. Install transducer adapters (5) into the hole that is remaining from the plug's removal. Tighten transducer adapters (5) only by a small amount.

7. Push top center magnetic transducer (3) into transducer adapters (5) until this adapter contacts the flywheel.

8. Pull the top center magnetic transducer (3) out of the transducer adapter by 1.6 mm (0.063 inch). Then, lightly tighten the knurled locknut.

9. Connect the cables from top center magnetic transducer (3) to 8T-5250 Engine Timing Indicator (1). Calibrate the indicator, and make any necessary adjustments.

   Note: See Special Instruction, SEHS8580 for more information on the calibration procedure.

10. Start the engine, and allow the engine to reach operating temperature. Then, run the engine at approximately one half throttle for eight to ten minutes. After this amount of time, measure the engine's timing.

11. Run the engine at increments of 100 rpm between 1000 rpm (base rpm) and high idle. Record the readings for engine timing, and then plot these readings onto a graph.

    Note: Use smaller increments to pinpoint the times when the timing advance starts. You can also use smaller increments to pinpoint the times when the timing advance stops.

    The engine's timing is set under the following conditions:

    • The readings for the timing indicator are within ±2.5 degrees of the timing that was calculated on the graph.

    • The angle of the change is approximately the same amount.

    Therefore, the engine's timing should be operating correctly.

    A timing adjustment may be needed under the following conditions:

    • The readings are NOT within ±2.5 degrees of the timing that was calculated on the graph.

    • The angle of the change is NOT smooth through the speed range.

    Refer to "Timing Adjustment by Timing Pin Method" for the static adjustment of the drive for the fuel injection pump.

If the automatic timing advance is not correct, repair the automatic timing advance unit, or replace the automatic timing advance unit.

Note: If you used the 8T-5250 Engine Timing Indicator (1) to set the engine timing, the timing pin may not fit into the slot in the fuel pump crankshaft with the flywheel at the top center position. (See "Finding the Top Center Position for No. 1 Piston".) This is a common result of using the dynamic timing indicator to set the timing instead of using the less accurate timing pin method.

Timing Adjustment by Timing Pin Method with 8T-5300 Engine Timing Indicator

Note: For all engines that are regulated for emission control, use the dynamic timing at 1000 rpm to measure the static fuel injection timing. Also, use the dynamic timing at 1000 rpm to set the static fuel injection timing. Do not use the pin timing for this measurement or for this setting.

1. Move the No. 1 piston to top center on the compression stroke. Remove the timing bolt.

   Note: Refer to "Finding the Top Center Position for No. 1 Piston".

2. Rotate the crankcase counterclockwise by 30 degrees.

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Illustration 5	g00319826
Timing Pin Cover (1) Timing pin cover. (2) Cover for timing gear. (3) Nut.

3. Remove timing pin cover (1) from the side of the fuel injection pump housing.

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Illustration 6	g00319828
Installed Fuel Pump Timing Pin (4) 6V-4186 Fuel Pump Timing Pin .

4. Install 6V-4186 Fuel Pump Timing Pin (4) in the fuel injection pump housing. See Illustration 6.

5. Slowly rotate the crankshaft counterclockwise until fuel pump timing pin (4) fits into the slot inside the fuel pump camshaft.

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NOTICE
Too much pressure on the timing pin can damage the fuel injection pump camshaft or the timing pin.

6. Place the timing bolt into the timing hole in the flywheel housing.

7. Slowly move the crankshaft counterclockwise until the fuel pump camshaft fits tightly against the timing pin. View the engine from the flywheel end during this procedure.

   This removes the gear clearance from the drive train.

   1. If the timing bolt can be installed in the flywheel and the timing pin can be installed in the fuel pump camshaft, the timing is correct.

   2. If either the timing bolt or the timing pin can NOT be installed, follow Steps 8 through 18.

8. Remove nuts (3) and timing pin cover (2) from the timing gear housing.

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Illustration 7	g00319830
Timing Gear for Fuel Injection Pump (5) Bolt.

9. Loosen bolt (5) that connects the timing gear to the fuel pump camshaft. Turn bolt (5) counterclockwise for three turns.

10. Install the 8S-2264 Puller Group, and loosen the timing gear from the fuel pump camshaft.

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Illustration 8	g00319832
Installed Puller Tools (6) 8S-2264 Puller Group (7) 8B-7560 Step Plate (8) 1B-3680 Bolt (9) 4B-5271 Washer

11. Rotate the flywheel clockwise to 60 degrees before No. 1 piston reaches the top center position.

12. Tighten bolt (5) finger tight. Make sure that fuel pump timing pin (4) fits inside the groove in the fuel pump camshaft.

13. Slowly rotate the crankshaft counterclockwise until the timing bolt can be installed in the flywheel.

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Illustration 9	g00319834
Installed Adapter on the Timing Gear (10) 4C-9874 Spanner Wrench .

14. Install 4C-9874 Spanner Wrench (10) onto the timing gear.

15. Maintain a torque of 60 to 70 N·m (45 to 50 lb ft) on spanner wrench (10) in a clockwise direction, and tighten bolt (5) that retains the timing gear to 270 ± 30 N·m (200 ± 20 lb ft).

16. Remove the timing bolt from the flywheel, and remove fuel pump timing pin (4) from the fuel pump camshaft.

17. Rotate the crankshaft counterclockwise for two revolutions.

    1. If the timing bolt can be installed in the flywheel and the timing pin can be installed in the fuel pump camshaft, the timing is correct.

    2. If either the timing bolt or the timing pin can NOT be installed, repeat Steps 8 through 17.

18. Use the 8T-5300 Engine Timing Indicator Group to verify the change to the engine's timing.