768C TRACTOR & 769C TRUCK POWER TRAIN Caterpillar

Differential And Carrier

Usage:

Remove Differential And Carrier

START BY:

a. remove rear axle housing and differential

b. remove axles (rear)

1. Drain the oil from the differential housing.

2. Remove two bolts, covers (1) and the shims from the differential housing.

3. Install a 3/8"-16 NC forged eyebolt in thrust pin (2), and remove the thrust pin from the differential housing. Remove the O-ring seal from the thrust pin.

4. Put identification marks on four brake cooling tubes (4), and remove the tubes.

5. Remove two clips (5) that hold four service brake tubes (7) to the support.

6. Put identification marks on four service brake tubes (7), and remove the tubes.

7. Remove slack adjuster (3) and manifold (6) from the support.

8. Fasten a hoist to support (8). Use the hoist to put the differential in a vertical position. Remove tool (A) from the differential.

9. Put tool (B) in position under the rear axle housing as shown to hold the axle housing from moving.

10. Remove nuts (9) that hold support (8) to the rear axle housing, and remove the support. The weight of the support is 295 kg (650 lb.).

11. Fasten a hoist and tooling (C) to the differential as shown. Remove the bolts that hold the differential to the differential housing. Install three 3/4"-10 NC forcing screws (10) in the differential. Tighten the forcing screws evenly to loosen the differential (11) in the differential housing. Remove the differential from the housing. The weight of the differential is 399 kg (880 lb.).

12. Remove the O-ring seal from the differential.

Install Differential And Carrier

1. Put the O-ring seal in position on differential (1).

2. Fasten a hoist and tooling (B) to the differential as shown. Align the hole in the differential with pin (2) in the differential housing, and put differential (1) in position on the housing. Install the bolts that hold the differential to the housing.

3. Fasten a hoist to support (3) as shown. Put the support in position on the differential housing.

4. Put SAE 30W oil on the washer, nut face and the threads, and install the washers and nuts (4) that hold the support to the differential housing. Tighten the nuts to a torque of 1485 ± 135 N·m (1100 ± 100 lb.ft.).

5. Install tool (C) on the differential. Remove tool (A), and lower lower support (3) until tool (C) is on the floor.

6. Install manifold (8) and slack adjuster (5) on support (3).

7. Install four service brake tubes (9), and install two clips (7) that hold the tubes to the support.

8. Install four brake cooling tubes (6).

9. Install O-ring seal (11) on thrust pin (10). Use a 3/8"-16 NC forged eyebolt, and install thrust pin (10) in the differential housing.

10. Put cover (12) in position on the differential housing without the shims, and install bolts (13). Tighten the bolts evenly until the thrust pin is against the bearing cap. Use a feeler gauge to measure the gap between the differential housing and cover (12).

11. Remove bolts (13) and cover (12).

12. Put shims (14), the same thickness as the gap measured in Step 10, plus 0.05 ± 0.03 mm (.002 ± .001 in.) and cover (12) in position on the differential housing, and install the bolts.

13. Fill the differential to the correct level with oil. See the Maintenance Guide.

END BY:

a. install rear axles

b. install rear axle housing and differential

Disassemble Differential And Carrier

START BY:

a. remove differential and carrier

1. Position the differential and carrier on tool (A). The weight of the differential and carrier is 399 kg (880 lb.).

2. Bend the lock away from bolt (3) on each side of the differential. Remove the bolts and locks (2) from caps (4).

3. Use tool (B), and loosen rings (5) 1/2turn.

4. Remove four nuts (1) and two caps (4) from the carrier.

5. Install a 25.4 mm (1 in.) bar (7) through the differential. Fasten a hoist to differential (8) as shown, and remove the differential from the carrier. The weight of the differentials is 197 kg (435 lb.).

6. Remove two rings (5) and cages (6) from the differential.

7. Use tooling (C) to remove two bearings (9) from differential (8).

8. Put an alignment mark on housings (10) and (11) for assembly purposes.

9. Remove the nuts and washer that hold housing (10) to housing (11). Fasten a hoist to housing (10) and the bevel gear, and remove them from housing (11). The weight of the housing and bevel gear is 84 kg (185 lb.).

10. Remove bolts (12) and housing (10) from bevel gear (13). The weight of the housing is 41 kg (90 lb.). The weight of bevel gear (13) is 42 kg (92 lb.).

11. Remove washer (14) and gear (15).

12. Fasten a hoist to spider (18) as shown, and remove the spider and pinions as an assembly. The weight of the spider and pinion assembly is 35 kg (78 lb.).

13. Remove four washers (17) and pinions (16) from the spider. Remove the bearings from pinions (16).

14. Remove gear (19) and the washer from housing (11).

15. Remove bolts (20).

16. Fasten a hoist and tooling (D) to carrier assembly (21), and position the carrier assembly on tooling (E) as shown. The weight of the carrier assembly is 186 kg (410 lb.).

17. Remove the bolt, washer, collar (23) and yoke (22) from the pinion.

18. Remove O-ring seal (25) from pinion (24).

19. Remove the bolts that hold cage (26) to the carrier. Install two 1/2"-13 NC forcing screws in the cage. Tighten the forcing screws evenly, and remove cage (26) and the shims from the carrier.

20. Remove O-ring seal (29), bearing cup (27) and seal (28) from cage (26).

21. Fasten a hoist and a 3/4"-10 NC forged eyebolt to pinion (24), and remove the pinion from carrier (21).

22. Remove bearing cones (30) and (31) from pinion (24).

23. Remove bearing cup (32) from the carrier.

Assemble Differential And Carrier

1. Lower the temperature of bearing cup (1), and install the bearing cup in the carrier.

2. Heat bearing cones (3) and (4) to a maximum temperature of 135°C (275°F), and install the bearing cones on pinion (2).

3. Fasten a 3/4"-10 NC forged eyebolt and a hoist to pinion (2). Put the pinion in position in carrier (5).

4. Lower the temperature of bearing cup (6), and install the bearing cup in cage (8).

5. Use tool (B), and install seal (7) in the cage as shown. Put clean oil on the lip of seal (7).

6. Install cage (8) on the carrier, and install every other bolt as shown.

7. Tighten bolts (9) evenly, and turn the pinion at the same time until a minimum torque of 4.0 N·m (35 lb.in.) is necessary to turn the pinion. Turn the pinion several more times. Loosen bolts (9) evenly, and turn the pinion at the same time until a torque of 4.0 ± 0.6 N·m (35 ± 5 lb.in.) is necessary to turn the pinion.

8. Use a feeler gauge to measure the gap between cage (8) and carrier (5) at four locations 90° apart. Find the average of the measurements.

9. Remove cage (8), but do not turn the pinion.

10. Install the correct thickness of shims found in Step 8 and cage (8) on the carrier. Install the bolts that hold the cage in place. Tighten the bolts to a torque of 105 ± 7 N·m (75 ± 5 lb.ft.).

11. Check the torque necessary to rotate the pinion. The torque necessary to rotate the pinion must be 4.0 ± 0.6 N·m (35 ± 5 lb.ft.).

12. If cage (8) has to be removed to add or remove shims, do not turn the pinion.

13. When the pinion bearing adjustment is correct, remove cage (8). Put O-ring seal (10) in position on the cage. Put clean oil on the O-ring seal. Put the cage in position on the carrier, and install the bolts. Tighten the bolts to a torque of 105 ± 7 N·m (75 ± 5 lb.ft.).

14. Put the O-ring seal in position on the pinion. Put clean oil on the O-ring seal.

15. Put yoke (13) and collar (12) in position on the pinion, and install the washer and bolt (11).

16. Put bolts (18) in position in housing (16) as shown.

17. Put washer (15) in position on dowels (17) in the housing. Install gear (14) on the washer.

18. Put the bearings, spiders (19) and washers (20) in position on spider (21).

19. Fasten a hoist to the spider assembly, and put it in position in housing (16). Make sure notches (23) in washer (20) align with dowels (22) in the housing.

20. Put gear (25) and washer (24) in position on the spiders.

21. Put housing (26) in position on bevel gear (28). Put 2P2506 Thread Lubricant on the face and threads of bolts (27), and install the bolts. Tighten the bolts to a torque of 440 ± 13 N·m (320 ± 10 lb.ft.).

NOTE: Make sure the alignment marks put on the small housing and housing (26) at disassembly are in alignment when assembled.

22. Put housing (26) in position on the small housing and spiders. Make sure the notch in the washer aligns with the dowels in housing (26), and install the washers and nuts. Tighten the nuts to a torque of 390 ± 13 N·m (290 ± 10 lb.ft.).

23. Use tooling (C) to turn the differential. The maximum torque needed to turn the differential two complete revolutions in each direction must not be more than 35 N·m (25 lb.ft.).

24. Heat bearing cones (29) and (30) to a maximum temperature of 135°C (275°F), and install the bearing cones on the housings as shown.

25. Install the bearing cup, cage (31) and ring (34) on each side of the differential (33).

26. Install a 25.4 mm (1 in.) bar (32) through the differential. Fasten a hoist to the differential, and install it in the carrier as shown.

27. Align dowel (36) in cap (35) with the hole in cage (31), and install the caps on each side of the differential. Install the nuts that hold the caps in place. Tighten the nuts to a torque of 14 N·m (10 lb.ft.) at this time.

28. Put the differential and carrier in position on tooling (H) as shown with the bevel gear teeth up.

29. Put tool (E) in position on the carrier and bevel teeth as shown.

30. Turn the bottom adjusting ring with tool (F) until there is 0.35 ± 0.13 mm (.014 ± .005 in.) backlash between the bevel gear and pinion.

31. Put tooling (G) in position on the carrier as shown with the tip of the indicator on housing (16). Set the indicator to read zero.

32. Turn top adjusting ring (34) to increase the distance between the top of the differential housing and the surface of the carrier where tooling (G) is mounted. Increase the distance by 0.51 to 0.64 mm (.020 to .025 in.).

33. Rotate the bevel gear several times in each direction; then back off top adjusting ring (34) until the indicator reads zero.

34. Turn top adjusting ring (34) in again to increase the distance between the top of the differential housing and the carrier. Increase the distance by 0.38 ± 0.05 mm (.015 ± .002 in.).

35. Check the backlash between the bevel and pinion. If the backlash has changed, repeat steps 29 through 34.