793C Off-Highway Truck/Tractor Power Train Caterpillar

Disassembly Procedure

Start By:

1. Remove the differential and bevel gear. Refer to Disassembly and Assembly, "Differential and Bevel Gear - Remove".

Note: For information on reusability of the components of the differential and bevel gear, refer to Guideline for Reusable Parts and Salvage Operations, SEBF8119, "Differential Components for Wheel Loaders, Off-Highway Trucks and Tractors, Articulated Dump Trucks, Wheel Tractors, Compactors, and Integrated Toolcarriers". Refer to Guideline for Reusable Parts and Salvage Operations, SEBF8227, "Salvage of Differential Housing Assembly Used on 785, 789, and 793 Trucks". Refer to Guideline for Reusable Parts and Salvage Operations, SEBF8200, "Salvage of Differential Bearing Cage Used on Off-Highway Trucks". Refer to Guideline for Reusable Parts and Salvage Operations, SEBF8138, "Salvage of Final Drive and Differential Thrust Washer Used in Off-Highway Trucks, Tractors, and Wheel Loaders".

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Illustration 1	g00515276

1. Use a suitable hoist to place differential and bevel gear (1) on a suitable repair stand. The differential and bevel gear weighs approximately 1185 kg (2612.5 lb).
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   Illustration 2	g00515289

2. Remove four bolts (3) and four washers. Remove pump outlet passage (2) with O-ring seal (4) (not shown) at the flange end and with O-ring seal (5) at the tube end.
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   Illustration 3	g00515290

3. Remove four bolts (7) and four washers from the flange end of pump inlet passage (6). Remove two bolts (9) and two washers from the bracket on the strainer. Remove the pump inlet passage with O-ring seal (8) (not shown) on the flange end.
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   Illustration 4	g00515292

4. Remove cotter pin (11), slotted nut (12), and washer (13). Use a suitable puller to remove gear (10) from the differential and bevel gear.
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   Illustration 5	g00515293

5. Remove four bolts (14) and four washers from pump (15). Remove the pump and shims (16). The pump weighs approximately 15 kg (33.1 lb).
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   Illustration 6	g00515295

6. Remove twelve bolts (18) and the washers. Remove gear (17). The gear weighs approximately 10 kg (22.1 lb).
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   Illustration 7	g00515297

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   Illustration 8	g00515298

7. Remove four bolts (19), the four washers, and four clips (20). Disconnect the flare fitting on tube (21). Remove the tube.

8. Disconnect the flare fitting on tube (24). Remove the tube.

9. Disconnect the flare fittings that are at each end of tube (23). Remove the tube. Remove fitting (22) and three fittings (26).

10. Remove three bolts (25) and three washers from the bracket at the base of the shroud.
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    Illustration 9	g00515299

11. Remove two bolts (28) and two washers from shroud (27). Remove the shroud.
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    Illustration 10	g00515302

12. Use Tool (C) to remove the bearing preload. Remove bolt (32), the washer, and keeper (33). Remove two bolts (30), two washers, bracket (29), and bearing cap (31).
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    Illustration 11	g00515304

    Note: The shroud was removed in Step 11, but the shroud still appears in Step 13.

13. Repeat Step 12 for the remaining bearing cap. Remove the bolt, the washer, and the keeper. Remove two bolts, two washers, and bearing cap (34).
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    Illustration 12	g00515306

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    Illustration 13	g00515311

14. Raise differential and bevel gear (35) from carrier (37). Remove bearing cup, cage, and slotted adjusting nuts (36) from each of the two bearing supports. The differential and bevel gear (35) weighs approximately 450 kg (992.1 lb). The small bearing cup, cage, and slotted adjusting nuts weighs approximately 12 kg (26.5 lb). The large bearing cup, cage, and slotted adjusting nuts weighs approximately 23 kg (50.7 lb).

    Note: For information on reusability of the bearing cage, refer to Guideline for Reusable Parts and Salvage Operations, SEBF8200, "Salvage of Differential Bearing Cage Used on Off-Highway Trucks".

    Note: For information on reusability of the bearing, refer to Guideline for Reusable Parts and Salvage Operations, SEBF8190, "Tapered Bearings Used in Off-Highway Trucks".

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    Illustration 14	g00515314

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    Illustration 15	g00515319

15. Remove slotted adjusting nut (38) and bearing (40) from the cage (39). Repeat this procedure for the remaining bearing cup, cage, and slotted adjusting nuts.
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    Illustration 16	g00515320

16. Mount the differential and bevel gear on a suitable repair stand with the bevel gear below the differential.

17. Use a suitable puller to remove bearing cone (41) from the differential.

    Note: For information on the salvage of the Differential Housing Assembly, refer to Guideline for Reusable Parts and Salvage Operations, SEBF8727, "Salvage of Differential Housing Assembly Used on 785, 789, and 793 Trucks".

    Note: For information on reusability of the bearing cone, refer to Guideline for Reusable Parts and Salvage Operations, SEBF8190, "Tapered Bearings Used in Off-Highway Trucks".

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    Illustration 17	g00515323

18. Remove eight bolts (42) and eight washers from housing (43). Remove the housing. The housing weighs approximately 43 kg (94.8 lb).
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    Illustration 18	g00515325

19. Remove thrust washer (44) from the housing that was removed in Step 18. The thrust washer is located on the two dowels.

    Note: There is a pin in housing (43) for each of the four pinion gear cages. The pin engages the pinion gear cage in order to prevent any rotation of the cage.

    Note: For information on reusability of the thrust washer, refer to Guideline for Reusable Parts and Salvage Operations, SEBF8183, "Salvage of Final Drive and Differential Thrust Washer Used in Off-Highway Trucks, Tractors, and Wheel Loaders".

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    Illustration 19	g00515327

20. Remove output gear (45) from the spider and the pinion gears. The output gear weighs approximately 28 kg (61.7 lb).
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    Illustration 20	g00515328

    Note: A manufactured lifting device is shown in this photo.

21. Use a suitable hoist to remove spider (46) and pinion gear (47) from housing (48). The spider and the pinion gear weigh approximately 50 kg (110.2 lb).
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    Illustration 21	g00515330

22. Remove the four pinion gears from the spider.

23. Place the pinion gears on Tool (A). Bend the locking tab of lock (50) away from nut (49). Remove the nut with Tool (B) (not shown). Remove the lock.
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    Illustration 22	g00515332

24. Remove bearing cone (51).
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    Illustration 23	g00515333

25. Remove bearing cup (52) and bearing cup (53) from pinion gear (47). Remove ring (56) and bearing cone (55) from bearing cage (54).

26. Repeat Step 23 through Step 25 for the three remaining pinions.
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    Illustration 24	g00515336

27. Remove remaining output gear (45) from the housing. The output gear weighs approximately 28 kg (61.7 lb).

    Note: For information on the reusability and the salvage of the output gear and the pinion gear, refer to Guideline for Reusable Parts and Salvage Operations, SEBF8119, "Differential Components for Wheel Loaders, Off-Highway Trucks and Tractors, Articulated Dump Trucks, Wheel Tractors, Compactors, and Integrated Tool Carriers".

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    Illustration 25	g00515337

28. Remove remaining thrust washer (44) from the housing. The thrust washer is located on the two dowels.

    Note: For information on reusability and salvage of the thrust washer, refer to Guideline for Reusable Parts and Salvage Operations, SEBF8131, "Salvage of Final Drive and Differential Thrust Washers Used in Off-Highway Trucks, Tractors, and Wheel Loaders".

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    Illustration 26	g00515338

29. Reposition the differential and bevel gear in order to access remaining bearing cone (57) (not shown). Remove the remaining bearing cone.

30. Mark the position of the bevel gear on the housing. Remove thirty bolts (58), thirty washers, and thirty nuts (59) from bevel gear (60). Remove the differential housing. The housing weighs approximately 95 kg (209.4 lb). The bevel gear weighs approximately 98 kg (216.1 lb).
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    Illustration 27	g00515339

31. Remove hose assembly (63)(not shown).

    Note: Hose assembly (63) connects elbow (61) to elbow (62).

32. Remove seventeen bolts (64) and seventeen washers. Use two 12mm X 1.75 thread forcing screws in order to separate cage (65) from the carrier.

    Note: The cage has six plugs which were installed with an epoxy adhesive. Do not attempt to remove these plugs.

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    Illustration 28	g00515340

33. Remove fitting (61), O-ring seal (66), and O-ring seal (67). Remove cage (65) and shims (68) from the carrier. The cage weighs approximately 50 kg (110.2 lb).
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    Illustration 29	g00515341

34. Remove bearing cup (69), seal (70), and O-ring seal (71) from cage (65).

    Note: For information on the reusability and salvage of the bearing cup, refer to Guideline for Reusable Parts and Salvage Operations, SEBF8190, "Tapered Bearings Used in Off-Highway Trucks".

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    Illustration 30	g00515342

35. Remove pinion gear and bearing cone (72) from the carrier. The weight of the pinion gear and bearing cone is approximately 70 kg (154.3 lb).
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    Illustration 31	g00515344

36. Remove bearing cup (73), shims (74), and fitting (62) from the carrier. Remove O-ring seal (75) and O-ring seal (76) from fitting (62). The carrier weighs approximately 588 kg (1296.3 lb).

    Note: For information on the reusability and salvage of the bearing cup, refer to Guideline for Reusable Parts and Salvage Operations, SEBF8190, "Tapered Bearings Used in Off-Highway Trucks".

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    Illustration 32	g00515345

37. Remove bearing cone (77) and bearing cone (78) from pinion gear (72). The pinion gear weighs approximately 95 kg (209.4 lb).

    Note: For information on the reusability and salvage of pinion gears, refer to Guideline for Reusable Parts and Salvage Operations, SEBF8119, "Differential Components for Wheel Loaders, Off-Highway Trucks and Tractors, Articulated Dump Trucks, Wheel Tractors, Compactors, and Integrated Tool Carriers".