3606 and 3608 Engines Caterpillar

Adjusting The Governor Linkage

Note: Before the governor linkage adjustment is made, the fuel injectors must be correctly synchronized. Refer to System Operation, Testing and Adjusting, "Fuel Injector Synchronization".

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Illustration 1	g01346109
Governor linkage (1) Synchronizing pin (2) Governor (3) Lever (4) Ring (5) Governor terminal shaft (6) Rod assembly (7) Governor control housing (8) Shaft (A) Location for synchronizing pin (B) Location for dial indicator

1. Remove the two plugs from location (B) and from location (A) on governor control housing (7) .

2. Remove synchronizing pin (1) from the storage location in the governor control housing. Install the synchronizing pin in the governor control housing at location (A) without the spacer. Tighten the synchronizing pin to 10 ± 2 N·m (7 ± 1 lb ft).

3. Rotate shaft (8) in the "FUEL ON" direction until the fuel stop lever is against the synchronizing pin. Hold the shaft (8) in position by installing a 1U-8795 Governor Torque Arm Tool on the opposite end of the governor terminal shaft. The rod assembly connects to the same end.

4. Install the 4C-6594 Timing and Fuel Setting Tool in the threaded hole at location (Y) of the fuel control housing.

   1. For the 4C-6594 Timing and Fuel Setting Tool, install the 5P-4814 Collet Clamp in the threaded hole at location (Y). Slide the 6V-3075 Dial Indicator with the 5P-7263 Indicator Contact Point into the 5P-4814 Collet Clamp. When the contact point seats against the fuel stop lever, slide the indicator inward or slide the indicator outward until the indicator dial reads +5.00 mm (+0.197 inch). Tighten the collet in order to hold the indicator in position. The indicator is now ready to be used.

5. Rotate governor terminal shaft (5) toward minimum fuel until governor rig pin (4) can be depressed. Put a 5/32 inch hex wrench in governor rig pin (4). Push the rig pin inward and turn the rig pin counterclockwise until the roll pin locks squarely behind the bracket.

Note: Governor rig pin (4) is used while the governor control rod assembly (6) is adjusted in order to stop the governor terminal shaft at a fixed position. This is done in order to synchronize the governor travel with the travel of the engine fuel control linkage. Engage the pin only when the engine is off.

6. Loosen synchronizing pin (2) for five to six turns.

7. Gently rotate governor terminal shaft (5) toward maximum fuel until contact is made with the governor rig pin. Hold shaft (3) in place. The dead weight that is used during unit injector synchronization may also be used in order to hold the governor terminal shaft against the governor rig pin.

8. Adjust rod assembly (6) .

   1. If the 4C-6594 Timing and Fuel Setting Tool is being used, adjust the rod assembly until the 6V-3075 Dial Indicator displays a reading of 5.00 mm (0.197 inch). Secure the rod assembly in place with the locknuts. Ensure that each rod end on the rod assembly has the same amount of thread engagement.

9. Rotate governor terminal shaft (5) toward minimum fuel. Put a 5/32 inch hex wrench in governor rig pin (4). Push the rig pin inward and turn the rig pin clockwise until the roll pin unlocks from the bracket. This puts the pin back into the pin's normal running position. The governor is now synchronized to the engine.

   When the 6V-3075 Dial Indicator is used, the reading should be between −4.50 mm (−0.177 inch) and −7.00 mm (−0.276 inch). If the reading is more positive than −4.50 mm (−0.177 inch), the linkage adjustment procedure must be repeated. −3.75 mm (−0.148 inch)is an example of a reading that is more positive than −4.50 mm (−0.177 inch).

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Personal injury or death can result from flying objects generated by engine overspeed. The engine could overspeed as a result of improper linkage assembly, adjustment, or governor deadband. Be prepared to stop the engine by activating the engine air shut-off or closing the air off to the air inlets.

10. The definition of governor deadband is the total amount of travel between the point of actual fuel shutoff and the actual "FUEL OFF" position. When the 6V-3075 Dial Indicator is used and when the reading of the maximum governor "FUEL OFF" is more positive than −4.50 mm (−0.177 inch), the governor deadband can be eliminated. −3.75 mm (−0.148 inch) is an example of a reading that is more positive than −4.50 mm (−0.177 inch). This can cause engine overspeed.

11. Tighten synchronizing pin (2) to a torque of 10 ± 2 N·m (7 ± 1 lb ft).

12. Gently rotate the governor terminal shaft toward the maximum fuel position until the fuel stop lever makes contact with synchronizing pin (2) .

13. When the 6V-3075 Dial Indicator is used, ensure that the dial indicator still reads +5.00 mm (+0.197 inch). If indicated reading is not correct, repeat Steps 3 through 9. If the indicated reading is correct, continue with the procedure. If the 6V-3075 Dial Indicator is used, adjust the dial indicator in order to read 0.00 mm (0.000 inch). This must be done before continuing the procedure.

14. Check the fuel setting. Refer to System Operation, Testing and Adjusting, "Fuel Setting Check".

15. Remove the 1U-8795 Governor Torque Arm Tool from the governor terminal shaft.

16. Remove synchronizing pin (2) from hole (A), and install the plug. Install the synchronizing pin and the spacer in the storage location.

17. Remove all tooling from location (B) in the governor control housing. Install the plug at location (B) .

18. Before starting the engine, put a mark on the governor position indicator at the point of minimum governor travel. This is the engine's stopped position.

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The engine may overspeed due to incorrect assembly or adjustment. Engine overspeed could result in personal injury, loss of life and/or property damage. Be prepared to stop the engine by activating the engine shutdown system or closing the air inlet lines.

Note: It may be necessary to back off the fuel ratio control setting in order to start the engine after this adjustment. This is done by first removing the plug from the right front corner of the governor's top cover. The governor is viewed from the end of the governor output shaft. Put a 3/16 hex wrench through the hole in the top cover until the wrench engages the adjustment screw. Turn the screw in the counterclockwise direction until the engine is able to start. This will take several turns.

19. Start the engine and operate the engine at low idle. Put a mark on the governor position indicator. This is the engine running position.

20. The engine running position of the governor must be six or more degrees above the engine's stopped position.

21. Operate the engine at high idle with no load in order to ensure that the governor can control the engine.

22. The fuel ratio control setting must be readjusted even if an adjustment was required in order to start the engine.

Adjust Fuel Ratio Control

There are two adjustments for the fuel ratio control. One adjustment is the fuel limit adjustment and the other adjustment is a gain rate. The gain rate is factory set and the gain rate must not be changed.

1. The correct fuel ratio control setting for 3600 Engines with Caterpillar 3161 Governors is +2.00 mm (+0.079 inch).

2. Remove the two plugs from locations (A) and (B) on governor control housing (7) .

3. Remove synchronizing pin (2) from the storage location in the governor control housing. Install the synchronizing pin in the governor control housing at location (A) without the washer. Tighten the synchronizing pin to 10 ± 2 N·m (7 ± 1 lb ft).

4. Rotate shaft (8) in the "FUEL ON" direction until the fuel stop lever is against the synchronizing pin. Hold the shaft in this position by installing a 1U-8795 Governor Torque Arm Tool on the opposite end of the governor terminal shaft. The rod assembly connects at this point.

5. Install the 4C-6594 Timing and Fuel Setting Tool in the threaded hole at location (Y) of the fuel control housing.

   1. For the 4C-6594 Timing and Fuel Setting Tool, install the 5P-4814 Collet Clamp in the threaded hole at location (Y). Slide the 6V-3075 Dial Indicator with the 5P-7263 Contact Point into the 5P-4814 Collet Clamp. When the contact point seats against the fuel stop lever, slide the dial indicator inward or slide the dial indicator outward until the dial indicator reads +5.00 mm (+0.197 inch). Tighten the collet in order to hold the dial indicator in position. The dial indicator is now ready to be used.

6. Remove the 1U-8795 Governor Torque Arm Tool from the governor terminal shaft. Ensure that the terminal shaft returns to the "FUEL OFF" position.

7. Remove synchronizing pin (2) from location (A), and install the plug. Install the synchronizing pin and install the spacer in the storage location.

8. Disconnect the boost line from the fuel ratio control. Plug the boost line in order to keep dirt and foreign material out of the engine.

9. Start the engine.

10. Rapidly move the speed control shaft in order to increase the speed of the engine. The rack position indicator will go up to the fuel limit position. The rack position indicator will pause momentarily at this position until the engine accelerates to high idle. The rack position indicator will then return to the idle rack position once the speed reaches high idle. Repeat this procedure several times and read the rack position indicator during each pause.

    The rack position indicator pauses at the limit for the fuel control linkage. This point is set by the fuel ratio control. If the fuel limit setting is in need of adjustment, proceed to Step 11. If the fuel limit setting is correct, stop the engine and proceed to Step 13.

11. Remove the plug from the right front corner of the governor's top cover. The governor is viewed from the end of the governor output shaft. Put a 3/16 hex wrench through the hole in the top cover until the wrench engages the adjustment screw. Rapidly move the speed control shaft in order to increase the speed of the engine. The rack position indicator will go up to the fuel limit position. The rack position indicator will pause momentarily at this position until the engine accelerates to high idle. The rack position indicator will then return to the idle rack position once the speed reaches high idle.

    During the momentary pause, turn the limit adjustment screw until the dimension on the rack position indicator is +2.00 mm (+0.079 inch).

    Turning the limit adjustment screw clockwise will decrease the limiter setting. Turning the limit adjustment screw counterclockwise will increase the limiter setting.

12. When the adjustment is correct, stop the engine. Remove the hex wrench and install the plug in the top cover. Put a seal wire through the holes in both the plug and the bolt head. Install the governor seal. Remove the plug from the boost line. Connect the boost line from the inlet manifold to the fuel ratio control.

13. Remove all tooling from location (Y) in the governor control housing. Install the plugs at location (Y) .