BUSHING 7F8816 - Caterpillar

Install Hydrostatic Power Control Unit Linkage (Internal)
1. Be sure both links (1) are in the correct position as shown in illustration B28836P1. 2. Install power control unit linkage (2) and servo valve stems (4) as a unit. Carefully slide the servo valve stems into the servo valves. The servo valve stems and servo valves are a matched set and have the same serial number stamped on them. If these components are not kept with each other when assembled, it is possible that the neutral pressure adjustments of the servo valves will not be correct. Before the linkage is completely tightened down, connect direction-speed link (3) to the bracket. 3. Lift the servo valve stems enough to install retainers (5). Install the six bolts that hold the retainers and power control unit linkage in place. Tighten the six bolts to a torque of 25 5 N m (18 4 lb ft). 4. Connect steering control rod ends (6) and (7) to the power control unit linkage.5. Do mechanical adjustment of hydrostatic power control unit linkage (internal). Refer to the topic "Hydrostatic Transmission Linkage Mechanical Adjustment" in Testing & Adjusting for the correct procedure.Disassemble Hydrostatic Power Control Unit Linkage (Internal)
Start By:a. remove hydrostatic power control unit linkage (internal)
Do not use an allen wrench to loosen detents (3) or (6). Loosen the locknut, and install another nut on the detent. Use the two nuts together to loosen the detents. The small allen screw in the detent is used to hold the spring in the detent under compression. If the small allen screw is turned in the detent, the detent, will not work correctly.
1. Remove bolts (1) and (2) and the spring washers. Loosen the locknuts and the detents (3) and (6) until they are clear of adjustment screws. Loosen adjustment screws (4) and (5). Make a record of the number of turns the screws are loosened from the original position. 2. Put identification marks on the two stems for assembly purposes as to their location on the linkage assembly. Use a screwdriver to remove spring (7) from the counterbore. Remove stem (8), and put it with the correct servo valve. Remove the other spring and stem in the same way. 3. Remove bolt (11) and the locknut. Remove snap ring (10). Remove bolt (13) and synch link (14).4. Remove bolt (9), the locknut and spacers (12) from the synch link. 5. Remove bolt (18), spacers (19) and locknut (20) from between centering spring (17).6. Remove bolt (15), spacer (16) and centering spring (17) from plate assembly (21). From this point on, the disassembly of both halves of the power control unit linkage is the same so only one half will be shown.
Typical Example7. Remove bolts (23) and steer cam assembly (22).
Typical Example8. Loosen plunger (25). Remove snap ring (24). Remove the servo stem lever from the steer cam.
Typical Example9. Move both arms of spring (29) to the opposite side of roller (27) and the pin to release the tension