69D and 769D Off-Highway Truck/Tractors and 771D Quarry Truck Power Train Caterpillar

Illustration 1	g01238419
(1) Pinion bearing (2) O-ring (3) Pinion (4) Pinion bearing (5) Differential carrier (6) Adjustment ring (7) Pin (8) Bolts (9) Cover (10) Shims (11) Seal (12) Bearing caps (13) O-ring (14) Bolts (15) Bevel gear (16) Yoke (17) Bolts (18) Cage (19) Bearing caps (20) Bolts (21) Shims (22) Pinions (23) Gears (24) Adjustment ring

Adjustment Procedure For Bevel Pinion Bearings

1. Install pinion bearing (1) and pinion bearing (4) on pinion (3) . Install the pinion in the carrier.

2. Install cage (18) and shims (21) .

   Note: Do not install yoke (16) , seal (11) , O-ring (2) , and O-ring (13) in cage (18) until the adjustment is made. Turn pinion (3) slowly while the adjustment is made.

3. Use shims (21) behind cage (18) to put a preload on pinion bearing (1) and pinion bearing (4) . Add shims (21) until the torque that is needed to turn pinion (3) is more than 4.0 N·m (35 lb in).

4. Turn pinion (3) for several revolutions. Change thickness of shims (21) so that a torque of 4.0 ± 0.6 N·m (35 ± 5 lb in) is needed to rotate the pinion.

5. Put lubricant on seal (11) and O-ring (2) and O-ring (13) . Install seal (11) and O-ring (2) on cage (18) . The lip of seal (11) must be toward pinion bearing (1) . Tighten bolts (20) to a torque of 135 ± 20 N·m (100 ± 15 lb ft). Install O-ring (13) and yoke (16) on pinion (3) .

   Note: After completing the adjustment, the distance between the center line of the axle and the end of pinion (3) should be 166.2 mm (6.54 inch).

Adjustment Procedure For Backlash And For Preload

1. Install the four pinions (22) and the two gears (23) in the differential. Tighten the eight bolts (14) that hold the two housing assemblies together to a torque of 395 ± 20 N·m (291 ± 15 lb ft).

2. Put the differential in "V" blocks. Turn one of the output gears for two revolutions clockwise. Then, turn the output gear for two revolutions counterclockwise. The maximum torque that is required to turn the output gear must not exceed 35 N·m (26 lb ft).

3. Install the differential into the carrier assembly.

4. Install the bearing caps (12) and (19) and the bolts (17) . Tighten the bolts (17) to a torque of 70 N·m (50 lb ft).

5. Mount the differential and the carrier assembly so that the bevel gear (15) is horizontal. The teeth of bevel gear (15) should be toward the top.

6. Use a dial indicator to check movement of ring (6) . Turn adjustment ring (6) until there is 0.35 ± 0.13 mm (0.014 ± 0.005 inch) backlash between bevel gear (15) and pinion (3) .

7. In order to get the preload on the carrier bearings, turn the adjustment ring (24) until dimension (B) has an increase of 0.50 to 0.65 mm (0.020 to 0.025 inch).

   Note: Use a dial indicator to measure the change in dimension (B) . Fasten the indicator on the differential assembly and put the pointer on the bearing cap (19) .

8. Remove the dial indicator and turn the bevel gear (15) in both directions for a total of 30 seconds in order to make sure that the bearings are seated.

9. Turn the adjustment ring (24) in order to decrease the end play at dimension (B) to 0 mm (0 inch).

10. Install the dial indicator. Install the dial indicator. Turn the adjustment ring (24) until dimension (B) increases by 0.38 ± 0.05 mm (0.015 ± 0.002 inch).

11. Use a dial indicator to recheck the backlash between the bevel gear (15) and the pinion (3) . Turn the adjustment rings (6) and (24) the same amount and turn the adjustment rings in the same direction until the backlash is 0.35 ± 0.13 mm (0.014 ± 0.005 inch).

    Note: There will be no change in the preload of the bearings if the adjustment rings are turned in this manner.

12. Tighten the four bolts (17) to a torque of 1100 ± 150 N·m (811 ± 111 lb ft).

Adjustment Procedure For The Pin

1. Install the differential carrier (5) into the axle housing.

2. Install pin (7) and the cover (9) . Do not install shims (10) at this time.

3. Tighten bolts (8) evenly until pin (7) is against bearing cap (12) . Use a feeler gauge in order to measure distance (A) between the axle housing and cover (9) .

4. Subtract 0.05 ± 0.02 mm (0.002 ± 0.001 inch) from this distance. This is the shim pack thickness. Assemble the shim pack with shims (10) .

5. Install shims (10) between the cover and the axle housing. Tighten bolts (8) to standard torque.

Note: This is a critical step.