793C Off-Highway Truck 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	g00859485

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 (2615 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	g00859402

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	g00859503

4. Remove cotter pin (11), slotted nut (12), and washer (13). Use a suitable puller to remove gear (10) from the lubrication pump.
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   Illustration 5	g00868689

5. Remove four bolts (14) and four washers from lubrication pump (15). Remove the lubrication pump and shims (16). The lubrication pump weighs approximately 15 kg (33 lb).
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   Illustration 6	g00859528

6. Remove 12 bolts (18) and the washers. Remove gear (17). The gear weighs approximately 10 kg (22 lb).
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   Illustration 7	g00859562

7. Remove bolts (18), washers, and clips (19) from lube line (22). Disconnect lube line (22) from fitting (23). Remove fitting (23). Remove bolts (21) and washers from shroud (20).
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   Illustration 8	g00859707

8. Disconnect fitting (24) from lube line (22). Remove lube line (22). Remove fitting (24). Remove bolts (25) and washers from the bracket at the base of the shroud (20). Remove shroud (20).
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   Illustration 9	g00859764

9. Disconnect fitting (26) from lube line (27). Remove lube line (27). Remove fittings (29) from lube line (28). Remove lube line (28). Remove fitting (30).
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   Illustration 10	g00859830

10. Remove bolts (32) and washers (33) from retainer (34). Remove retainer (34) and shims (31) behind retainer (34).
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    Illustration 11	g00859836

11. Remove bolts (35) and washers from the heel support bearing cup (37). Remove bolts (36) from the heel support bearing cap (38). Remove the heel support bearing cap (38) and remove the heel support shims (39).
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    Illustration 12	g00859865

12. Remove bolts (40) and washers from the toe support bearing cap (41). Remove toe support bearing cap (41).
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    Illustration 13	g00859900

13. Raise differential and bevel gear (1) from carrier housing (42). The differential and bevel gear (1) weighs approximately 450 kg (990 lb).
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    Illustration 14	g00859955

14. Remove bearing cage (43), bearing race (44), and spiral lockring (45). These three parts should come off together.

    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".

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    Illustration 15	g00860819

15. Position the differential and bevel gear in order to access the heel support bearing cup (37) (not shown) and the two remaining heel support bearing cones (46). Use a suitable puller to remove the heel support bearing cones (46) and the heel support bearing cup (37) (not shown) from the flanged half of the differential housing (47).

    Note: In Illustration 15, only one of the heel support bearing cones (46) is shown.

    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 16	g00860050

16. Position the differential and bevel gear on a suitable repair stand. Ensure that the heel support side of the differential and bevel gear is facing upward.

17. Use a suitable puller to remove the straight roller bearing (48) from the plain half of the differential housing (49).

    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". This referenced publication is applicable to the straight roller bearing that is located on the toe support side of the differential housing.

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    Illustration 17	g00860082

18. Remove eight bolts (50) and eight washers from the plain half of the differential housing (49). Remove the plain half of the differential housing (49). The plain half of the differential housing (49) weighs approximately 42 kg (93 lb).

    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".

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    Illustration 18	g00860234

19. Remove thrust washer (51) from the plain half of the differential housing (49) that was removed in Step 18. The thrust washer is located on dowels.

    Note: There are pins (52) in the plain half of the differential housing (49) for each of the four pinion gears. The pins (52) engage in the retainers of the pinion gears in order to prevent rotation of the retainers of the pinion gears.

    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	g00860462

20. Remove output gear (53) from the spider and the pinion gears. The output gear weighs approximately 28 kg (62 lb).
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    Illustration 20	g00860558

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

21. Use a suitable hoist in order to remove spider (54) and pinion gears (55) from the flanged half of differential housing (47). The spider (54) and the pinion gears (55) together weigh approximately 50 kg (110 lb).

22. Remove the four pinion gears (55) from the spider (54).
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    Illustration 21	g00860585

23. Place the pinion gears (55) on Tool (A). Bend the locking tab of nut lock (57) away from nut (56). Remove the nut with Tool (B) (not shown). Remove the nut lock (57).
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    Illustration 22	g00860615

24. Remove bearing cone (58).
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    Illustration 23	g00860624

25. Remove bearing cup (60) (not shown) and bearing cup (61) (not shown) from pinion gear (55). Remove ring (63) and bearing cone (59) from the retainers of the pinion gears (62).

26. Repeat Step 23 through Step 25 for the three remaining pinion gears.
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    Illustration 24	g00860796

27. Remove remaining output gear (53) from the flanged half of the differential housing (47). The output gear weighs approximately 28 kg (62 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	g00860863

28. Remove remaining thrust washer (51) from the flanged half of the differential housing (47). The thrust washer (51) is located on 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	g00868361

29. Mark the position of the bevel gear (64) on the flanged half of the differential housing (47), as shown. Remove 30 bolts (65), 30 washers, and 30 nuts (66) from bevel gear (64). Remove the flanged half of the differential housing (47) from the bevel gear. The flanged half of the differential housing (47) weighs approximately 77 kg (170 lb). The bevel gear ( 64) weighs approximately 98 kg (220 lb).
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    Illustration 27	g00860966

30. Remove hose assembly (68) from the pinion bearing cage (67). Remove 17 bolts (69) and 17 washers. Use two 12 mm X 1.75 thread forcing screws in order to separate the pinion bearing cage (67) from the carrier housing (42).

    Note: The pinion bearing cage (67) has six plugs (70) which were installed with an epoxy adhesive. Do not attempt to remove plugs (70).

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    Illustration 28	g00861008

31. Remove pinion bearing cage (67) and shims (71) from the carrier housing (42). The pinion bearing cage (67) weighs approximately 55 kg (121 lb).
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    Illustration 29	g00861024

32. Remove bearing cup (72), seal (73), and O-ring seal (74) from pinion bearing cage (67).

    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	g00861060

33. Remove pinion gear (75) and the attached bearing cones from the carrier housing (42) (not shown). The weight of the pinion gear (75) and the attached bearing cones is approximately 101 kg (220 lb).
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    Illustration 31	g00861091

34. Remove bearing cup (76) (not shown) and shims (77) (not shown) from the carrier housing (42).

    Note: The carrier housing (42) weighs approximately 588 kg (1300 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	g00861111

35. Remove bearing cone (78) and bearing cone (79) from pinion gear (75). The pinion gear (75) alone weighs approximately 70 kg (155 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".