784C and 785C Off-Highway Trucks Machine Systems Caterpillar

Disassembly Procedure

Start By:

1. Remove the pump drive. Refer to Disassembly and Assembly, "Pump Drive - Remove".

Note: Cleanliness is an important factor. Before the disassembly procedure, the exterior of the component should be thoroughly cleaned. This will help to prevent dirt from entering the internal mechanism.

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Illustration 1	g00537725

1. Position the pump drive in a fixture or a vise. The weight of the pump drive is approximately 68 kg (149.9 lb).

2. If necessary, remove two dowels (2) from cage assembly (3).

   Note: The dowels are part of the gear pump for brake retract and oil cooling.

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   Illustration 2	g00486591

3. Remove yoke assembly (4) from the spline that is located inside pump drive housing (1).
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   Illustration 3	g00537727

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   Illustration 4	g00574328

4. Remove six bolts (5) and the washers in order to remove bearing cage (6) from pump drive housing (1). If necessary, use two 1/2 inch X 13 NC forcing screws (X) in order to remove bearing cage (6).

5. Remove six bolts (7) and the washers in order to remove cage assembly (3) from pump drive housing (1). If necessary, use two 1/2 inch X 13 NC forcing screws (X) to remove cage assembly (3).
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   Illustration 5	g00486597

6. Remove shim pack (10) and O-ring seal (8) from bearing cage (6).

7. Use Tooling (A) (not shown) in order to remove roller bearing cup (9) from bearing cage (6).
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   Illustration 6	g00486598

8. Remove shim pack (12) and O-ring seal (11) from cage assembly (3).

9. Use Tooling (A) (not shown) in order to remove roller bearing cup (13) from cage assembly (3).
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   Illustration 7	g00486599

10. Remove pump drive gear (14) from the upper portion of pump drive housing (1).
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    Illustration 8	g00486601

11. Remove pump drive gear (15) from the lower portion of pump drive housing (1).
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    Illustration 9	g00486602

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    Illustration 10	g00486605

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    Illustration 11	g00486613

12. Remove four bolts (18) and the washers in order to remove governor control shaft (17) from pump drive housing (1).

13. Support pump idler gear (16) during the removal of governor control shaft (17) from pump drive housing (1).

    Note: If necessary, use two 1/2 inch X 13 NC forcing screws to remove governor control shaft (17).

14. Lower pump idler gear (16) from the center position of pump drive housing (1) to the lower opening after governor control shaft (17) is removed. Remove pump idler gear (16) from pump drive housing (1).
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    Illustration 12	g00537690

15. Place pump idler gear (16) onto a suitable bench. Use Tooling (B) (not shown) in order to remove roller bearing assembly (19) from pump idler gear (16).
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    Illustration 13	g00486618

16. Place governor control shaft (17) onto a suitable bench. Remove spacer (20) from governor control shaft (17). Use Tooling (B) (not shown) in order to remove roller bearing assembly (21) from governor control shaft (17).

17. Remove O-ring seal (22) from governor control shaft (17). Remove shim pack (23) from governor control shaft (17).
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    Illustration 14	g00537852

18. Use Tooling (A) (not shown) in order to remove roller bearing cup (25) from pump idler gear (16).

19. Remove lockring (24) from pump idler gear (16).

20. Use Tooling (A) (not shown) in order to remove roller bearing cup (26) from pump idler gear (16).
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    Illustration 15	g00538074

21. If necessary, use Tooling (B) (not shown) in order to remove roller bearing cone (27) and (28) from pump drive gear (15).

22. If necessary, use Tooling (B) (not shown) in order to remove roller bearing cone (29) and (30) from pump drive gear (14).
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    Illustration 16	g00486647

23. Remove pump drive housing (1) from the vertical position in the vise or the suitable fixture. Position pump drive housing (1) onto a suitable bench.
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    Illustration 17	g00487347

24. Use a suitable drift in order to remove seal ring (31) from pump drive housing (1).
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    Illustration 18	g00538041

25. Remove lip seal (32) from pump drive housing (1).

26. Remove plug (33) and the O-ring seal from pump drive housing (1).
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    Illustration 19	g00538072

27. Remove plug (34) and the O-ring seal from pump drive housing (1).
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    Illustration 20	g00537692

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    Illustration 21	g00537693

28. If necessary, use Tooling (A) (not shown) in order to remove bearing cups (35) and (36) from pump drive housing (1).