UG ACTUATOR Caterpillar


Operation & Maintenance

Usage:

UG Actuator Maintenance

Oil

Replace the actuator oil if it is contaminated. Change the oil if it is suspected of contributing to instability. Check the color of the oil in the sight glass periodically. Replace if:

* the oil has darkened and smells "burnt" or
* the oil has a "milky" color (usually means that the oil has water condensation).

Oil that has been carefully selected to match the operating conditions of the engine and is compatible with actuator components should give a dependable service life between oil changes. Check oil conditions regularly.

Every 8000 Service Hours or Three Years

Replace Oil

1. Install a 1/8 NPT nipple and drain tube onto the drain cock (if equipped). Place the other end of the drain tube into a suitable container to catch the oil.

2. Remove the oil fill cap and open the drain cock. Drain oil into a suitable container. If no drain cock is equipped, remove the drain plug and drain the oil into a suitable container.

3. After the oil has drained, close the drain cock and remove the drain tube and nipple. If the drain plug was used, clean and install the drain plug. Do not reuse the drained oil. Properly dispose or recycle the drained oil.

4. Remove the oil fill cap. Pour clean engine oil into the opening until the oil drains out of the sight glass weep hole. Replace the oil fill cap.

NOTE: The oil level must be checked again immediately after the engine has been started. Adjust the oil level to the mid point (black line) of the sight gauge. To adjust the oil level, add or remove oil from the actuator. Remember, the engine must be stopped before draining oil from the actuator.

Check for Proper Operation

After filling the actuator with engine oil as recommended, check for proper operation. Refer to the Service Manual for your engine, or refer to your Caterpillar dealer for more information.

UG Actuator Linkage

Adjust UG Actuator Linkage

The governor actuator linkage must be adjusted to synchronize the actuator travel with the engine fuel control linkage travel.


Typical in-line set up. (1) Actuator. (2) Rod assembly. (3) Synchronizing pin. (4) Plug (synchronizing position). (5) Plug (dial indicator position). (6) Linkage control housing. (7) Fuel stop lever and shaft. (8) Actuator lever. (9) Actuator shaft.


Typical vee set up. (1) Actuator. (2) Rod assembly. (3) Synchronizing pin. (4) Plug (synchronizing position). (5) Plug (dial indicator position). (6) Linkage control housing. (7) Fuel stop lever and shaft. (8) Actuator lever. (9) Actuator shaft.


(3) Synchronizing pin. (7) Fuel stop lever and shaft. (10) Fuel setting screw.

1. Install the rod assembly exactly as shown in the previous typical set up drawings.

2. Remove plug (5) from the dial indicator position. Remove plug (4) from the synchronizing position.

3. Remove synchronizing pin (3) from the storage position in the linkage control housing (6). Remove the spacer from the synchronizing pin and install the pin in the control housing, where plug (4) was removed. Tighten the synchronizing pin to a torque of 10 ± 2 N·m (89 ± 18 lb in).

4. Rotate the fuel stop lever and shaft (7) in the fuel "ON" direction until Surface A of the fuel stop lever is against the synchronizing pin. Hold the shaft in this position.

NOTE: It is important to exert a firm, steady (but not excessive) force on the shaft and linkage during adjustment.

5. Install the 6V3075 Dial Indicator in the test port where plug (5) was removed. Install the 5P4814 Collet in test port (5). Slide the 6V3075 Dial Indicator with the 5P7263 Contact Point into the collet. When the contact point seats against the fuel stop lever (7) on Surface B, slide the indicator IN or OUT, until the indicator dial reads +4.00 mm (+.157 in). Tighten the collet to hold the indicator in this position. The indicator is now ready to be used.

6. Rotate governor actuator shaft (9) to the minimum fuel position and hold in place.

7. The dial indicator should read between -5.50 mm (-.217 in) and -8.00 mm (-.315 in). If the readings are not correct loosen the locknuts on rod assembly (2) and adjust length.

Tighten locknuts. Be sure each rod end on the rod assembly has the same amount of thread engagement. Rotate fuel stop lever (7) in the "FUEL ON" direction. The dial indicator should read +4.00 mm (+.157 in). If the reading is not correct repeat Steps 5 through 7.

8. "Deadband" is defined as: the total amount of travel between the point of actual fuel shutoff and the actuator "FUEL OFF" position. A small amount of "Deadband" is required for correct engine operation. If the actuator "FUEL OFF" reading is more positive than the (negative) values given in Step 7, the "Deadband" could be eliminated and result in an engine overspeed.

------ WARNING! ------

Incorrect linkage assembly or adjustment, could allow engine overspeed and result in personal injury and/or property damage.

--------WARNING!------

9. Check the fuel setting. Refer to the topic "Fuel Setting Check" in the service manual for your engine.

10. Remove the synchronizing pin from the linkage control housing. Replace the spacer and install the pin in the storage location. Install plug (4) in the housing.

NOTE: After assembly and adjustments are complete, shafts must rotate freely and linkage must return to shutoff position when rotated and released.

11. Before starting the engine, put a mark on the actuator position indicator at the point of minimum actuator travel. This is the engine stopped position.

------ WARNING! ------

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 emergency air shutoff or closing the air inlet lines.

--------WARNING!------

12. Start the engine and operate it at low idle. Put a mark on the actuator position indicator. This is the engine running position.

13. The engine running position of the actuator should be six degrees above the engine stopped position.

14. Operate the engine at high idle with no load, to be certain the actuator can control the engine.

Back to top
The names Caterpillar, John Deere, JD, JCB, Hyundai or any other original equipment manufacturers are registered trademarks of the respective original equipment manufacturers. All names, descriptions, numbers and symbols are used for reference purposes only.
CH-Part.com is in no way associated with any of the manufacturers we have listed. All manufacturer's names and descriptions are for reference only.