918F WHEEL LOADER POWER TRAIN Caterpillar

Transmission

Usage:

Disassemble Transmission

Start By:

a. remove engine and transmission

b. separation of transmission from engine

c. disassemble and assemble torque converter

1. Remove the transmission control valve from the body of the transmission. Install tool (J) over the transmission control valve porting.

2. Remove the large O-ring seal (1) from the torque converter housing.

3. Fasten tooling (F) and a hoist to torque converter.

4. Remove bolts (3) that holds housings (2) and (4) together.

5. Lift torque converter (5) and housing (20 off of housing (4).

6. Turn housing (2) over. Remove three bearings and race (6) if necessary.

7. Remove forward low and forward high clutch group (7) as a unit with tool (G) from housing (4). Weight of the unit is 27 Kg (60 lb).

NOTE: After the disassembly of each clutch group, shaft plugs (X) must be removed for inspection and cleaning of the oil passages. Use a suitable punch and drive the center portion of the plug down into the shaft. Drill the remainder of the aluminum plug out of its bore being careful not to drill any portion of the outer of the outer walls of the plug bore. To clean the shafts either use shop air or submerge the shafts into any desirable cleaning solution.

8. Disassemble forward low clutch group by removing retainer ring (8) with tool (A) and then remove thrust washer (9) from the forward low end of clutch group.

9. Remove retainer ring (10) with tool (A) and then remove gear (11).

10. Remove retainer ring (12) with tool (B). Remove hub (13). Remove plates and discs (14).

11. Remove thrust washer (15).

NOTE: Thrust washer (15) may stick to the inside of hub (13) when the hub is removed.

12. Remove bearing assembly (16) from hub (13) only if it is damaged.

13. Put forward low clutch group in a press. Use tool (C) and compress the spring. Remove retainer ring (17).

14. Remove retainer (18) and spring (19).

15. Release piston (20) by blowing shop air into lube passage (21). Remove piston (20) from the clutch group housing.

16. Remove three seal rings (22) from the shaft if they are damaged.

17. Remove seal rings (23) and (24) from the piston if they are damaged.

18. Disassemble forward high clutch group by removing retainer ring (25) with tool (A). Remove thrust washer (26).

19. Remove retainer ring (27) with tool (A) and then remove gear (28).

20. Remove hub (29).

21. Check the condition of bearing assembly (30) and remove it from hub (29) if necessary.

22. Remove thrust washer (31). Remove retainer ring (32) with tool (B). Remove plate and discs (33).

NOTE: Take note of the number and order of plates and discs for assembly purposes.

23. Put the forward high clutch group in position in a press. Use tool (C) to remove retainer ring (34).

24. Remove spring retainer (35) and spring (36).

25. Remove piston (37) by turning the clutch group over and blowing shop air into lube passage (38).

26. Remove seal rings (39) and (40) from the piston.

27. Remove reverse-second gear clutch group (41) from the housing with tool (G). Weight of the gear clutch group is 32 Kg (70 lb).

28. Disassemble the reverse clutch group by removing retainer ring (42) with tool (A). Remove thrust washer (43) from the clutch group.

29. Remove retainer ring (44) with tool (A). Remove gear (45).

30. Remove hub assembly (46).

31. Remove thrust washer (47).

32. Remove retainer ring (48) with tool (B). Remove plates and discs (49).

NOTE: Take note of the number and order of the plates and discs for assembly purposes.

33. Check the condition of bearing assembly (50) in hub assembly (46). Remove the bearing assembly only if necessary.

34. Put the reverse clutch group in a press. Using tool (C), remove retainer ring (51) with tool (A).

35. Remove spring retainer (52) and then remove spring (53).

36. Release piston (54) by blowing shop air into lube passage (55).

37. Remove three seal rings (56) only if they are damaged.

38. Remove seal rings (57) and (58) from the piston.

39. Disassemble the second gear clutch group by installing a suitable puller under gear (59). With the puller, pull gear (59), spacer (60) and bearing (61) at the same time.

40. Remove spacer (62), thrust washers (63) and (64).

NOTE: Use steps 29 through 38 for the remaining disassembly of the second gear clutch group. In step 34, use tool (H) instead of tool (C).

41. Remove first and third gear clutch group (65) from the housing with tool (G). Weight of the gear clutch group is 50 Kg (110 lb).

42. Disassemble third gear clutch group by removing retainer ring (66) with tool (A). Remove thrust washer (67).

43. Remove retainer ring (68) with tool (A). Remove gear (69).

44. Remove hub assembly (70).

45. Remove thrust washer (71).

46. Remove retainer ring (72) with tool (B). Remove plates and discs (73).

NOTE: Take note of the number and order of the plates and discs for assembly.

47. Remove bearing assembly (74) from hub assembly (70).

48. Put the third gear clutch group in position in a press. Using tool (C), remove retainer ring (75) with tool (A).

49. Remove spring retainer (76) and spring (77).

50. Release piston (78) by blowing shop air into lube passage (79). Remove piston (78).

51. Remove three seal rings (80) from the shaft only if they are damaged.

52. Remove seals (81) and (82) from the piston.

53. Disassemble first gear clutch by installing tool (D) through the holes in gear (83). Pull gear (83), thrust washer (84) and bearing (85) together as a group.

54. Remove thrust washer (86). Remove retainer ring (87) with tool (E). Remove gear (88).

55. Remove hub assembly (89).

56. Remove thrust washers (90) and (91). Remove retainer ring (92) with tool (B). Remove plates and discs (92).

NOTE: Take note of the number and order of the plates and discs for assembly purposes.

57. Remove retainer ring (94) that thrust washers (90) and (91) rested open.

58. Remove bearing assembly (95) from hub assembly (89).

59. Put the first gear clutch group in position in a press. Using tool (C), compress the wave springs and remove retainer ring (96) with tool (A).

60. Remove balance piston (97) from the clutch gear housing.

61. remove wave springs (98) and (99) from the clutch gear housing.

62. Turn the clutch group over and remove piston (100). Blowing air into the lube passage in the shaft may be necessary to release the piston.

63. Remove seals (101), (102) and (103) from the piston and spring retainer.

64. Remove input shaft (104) from the transmission housing.

65. Remove carrier (105) with seal ring (106). Remove bearing (107) and gear (108) from input shaft (104).

66. Remove bearing (109) and gear (110) from the bottom end of the input shaft (104).

67. Remove bearing (111) and bearing cups (112) if they are damaged.

68. Remove bolt (113), washer (114) and yoke (115) from the front of the output shaft.

69. Remove bolt and washer (116) from the parking brake end of the output shaft.

70. Remove O-ring seal (117). Lift yoke (118) brake drum (119) off of the parking brake as a unit.

71. Remove four bolts (120) holding parking brake assembly and remove plate (121).

72. Remove parking brake assembly (122) and lever (123).

73. Remove eight bolts (124) and install two of the bolts in the threaded holes to use as forcing screws.

74. Turn the bolts down to force up housing (125) and separate it from the transmission housing.

75. Remove shims (126) from the output shaft housing.

76. Remove O-ring seal (127) from bearing cage (125).

77. Remove bearing cup (128) and lip seal (129) from bearing cage (125).

78. Remove nuts (130) and remove cover (131).

79. Remove output shaft and gear (132).

80. Remove three bolts (133) and shield assembly (134).

81. Remove bearing cup (135) and lip seal (136)

82. Remove bearing (137) from the front end of the output shaft.

83. Remove bearing (138), retainer ring (139) and gear (140) from the parking brake end of the output shaft.

Assemble Transmission

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NOTICE

If it is necessary to rebuild any of the clutch groups, take special notice in the areas on the clutch plates located adjacent to the spring washers (Belleville type). Some wear might be noticed on the clutch plates. This wear is the result of the rougher texture on the washers imprinting onto the adjacent smooth plates when the clutch is engaged. At the time of rebuild, these "textured" plates which could be reused should NOT be used next to a friction disc. Reuse next to a disc could result in the rapid wear of the disc and cause clutch failure. These plates if or when reused, should be placed at locations where the "textured" surface will not be in contact with a friction material surface.

1. Heat bearing (138) to a temperature of 135° C (275° F). Install gear (140) and retainer ring (139) on the parking end of the output shaft. Install bearing (138) on the shaft.

2. Heat bearing (137) to a temperature of 135° C (275° F) and then install it on the front end of the output shaft.

3. Coat the seal bore with 7M7260 Liquid Gasket Material and allow it to dry before installing the seal.

4. Install lip seal (136) in the seal bore making sure that the lip of the seal is installed with the lip toward the bearings (inside).

5. Lower the temperature of bearing cup (135). Install bearing cup (135) and make sure it is seated.

6. Install shield assembly (134) and three bolts (133).

7. Install output shaft and gear (132).

8. Install cover (131) with four bolts (130).

9. Coat the seal bore in bearing cage (125) with 7M7260 Gasket Material and allow it to dry before installing the seal.

10. Install lip seal (129) in the seal bore making sure that the lip of the seal is installed with the lip toward the bearings (inside).

11. Lower the temperature of bearing cup (128). Install bearing cup (128) and make sure it is seated.

12. Install O-ring seal (127) on bearing cage (125).

13. Install shims (126) on the output shaft housing. Use shims as necessary to get 0.06 to 0.13 mm (.002 to .005 inch) endplay on the output shaft.

14. Put bearing cage (125) in position on the output shaft housing and install eight bolts (124) that hold it.

15. Install parking brake assembly (122) and lever (123) as shown.

16. Install plate (121) and four bolts (120).

17. Install brake drum (119) and yoke (118) on the parking brake as a unit. Install O-ring seal (117).

18. Install bolt and washer (116) on the parking brake end of the output shaft.

19. Install yoke (115), washer (114) and bolt (113) on the front of the output shaft.

20. Lower the temperature of bearing cups (112) and install them in the housing. Make sure that the bearing cups are seated. Install bearing (111) in the housing with tool (D).

21. Install gear (110) on the bottom end of input shaft (104). Heat bearing (109) to a temperature of 135° C (275° F) and then install it in it's respective position on the input shaft.

22. Install gear (108) on input shaft (104). Heat bearing (107) to a temperature of 135° C (275° F) and install it on the input shaft.

23. Install seal ring (106) on carrier (105). Install carrier (105) on the input shaft.

24. Install input shaft (104) in the transmission housing.

25. Install seals (101), (102) and (103) on the piston and spring retainer.

26. Put a generous amount of clean oil on piston (100) and carefully install it into the clutch housing.

27. Install wave springs (98) and (99) over the piston.

28. Install balance piston (97) in the clutch housing.

29. Put the first clutch gear group in position in a press and then use the press and tool (C) to compress the wave springs and install retainer ring with tool (A).

30. Lower the temperature of bearing assembly (95) and install it in hub assembly (89).

31. Install retainer ring (94) on the shaft.

32. Install plates and discs (93). Install retainer ring (92) with tool (B). Install thrust washers (90) and (91) that rest on retainer ring (94).

33. Install hub assembly (89).

34. Install gear (88) then install retainer ring (87) with tool (E). Install thrust washer (86).

35. Install gear (83), thrust washer (84) and bearing (85) on the shaft.

NOTE: This completes the assembled of the first gear clutch group.

NOTE: See Procedure To Measure Running Clearance to check for proper clutch assembly in Specifications.

36. Install seals (81) and (82) on piston (78) [third gear clutch group].

37. Install third gear clutch piston (78) in the clutch housing with tool (H).

38. If seals (80) were damaged, install new seals on shaft (79).

39. Install spring (77) and then install spring retainer (76).

40. Put the third gear clutch group in position in a press. Using tool (C), install retainer ring (75) with tool (A).

41. Lower the temperature of bearing (74) and install it in hub assembly (70).

42. Install plates and discs (73). Install retainer ring (72) with tool (B).

43. Install thrust washer (71).

44. Install third gear clutch hub (70).

45. Install gear (69). Install retainer ring (68) with tool (A).

46. Install thrust washer (67). Install retainer ring (66) with tool (A).

NOTE: This completes the assembly of the third gear clutch group.

47. Fasten tool (G) and a hoist to the first and third gear clutch group. Install first and third gear clutch group (65) in the transmission housing.

NOTE: Do Steps 48 through 52 for the assembly of the clutch portion of the second gear clutch group. in Step 52, use tool (K) instead of tool (C).

48. Assemble the remainder of the second gear clutch group by installing thrust washers (63) and (64) over the shaft. Install spacer (62).

49. Install gear (59), spacer (60) and bearing (61) on the shaft.

50. Install seal rings (57) and (58) on the reverse gear clutch piston (54).

51. If seal rings (56) were damaged, install new ones on shaft (55).

52. Install clutch piston (54) in the clutch housing with tool (H).

53. Install spring (53) and then install spring retainer (52).

54. Put the reverse clutch group in position in a press. Using tool (C). Install retainer ring (51) with tool (A).

55. Lower temperature of bearing assembly (50) and install it in hub assembly (46).

56. Install plates and discs (49). Install retainer ring (49) with tool (B).

57. Install thrust washer (47).

58. Install hub assembly (46).

59. Install (45). Install retainer ring (44) with tool (A).

60. Install thrust washer (43) on the clutch group. Install retainer ring (42) with tool (A).

NOTE: This completes the assembly of the reverse second gear clutch group.

NOTE: See Procedure To Measure Running Clearance to check for proper clutch assembly in Specifications.

61. Fasten tool (G) and a hoist to reverse-second gear clutch group (41) and install it in the transmission housing.

62. Install seal rings (39) and (40) on the forward high clutch group piston.

63. Install piston (37) in the clutch housing with tool (H).

64. Install spring (36) and spring retainer (35) in the clutch housing.

65. Put the forward high clutch group in position in a press. Use tool (C) to install retainer ring (34).

66. Install plate and discs (33). Install retainer ring (32) with tool (B).

67. Instal thrust washer (31).

68. If bearing (30) was removed because of damage, lower the temperature of a new one and install it in hub (29).

69. Install hub (29) in the clutch housing.

70. Lower the temperature of gear (28). Install gear (28) and install retainer ring (27) with tool (A).

71. Install thrust washer (26) and install retainer ring (25) with tool (A).

NOTE: This completes the assembly of the forward high clutch group.

NOTE: See Procedure To Measure Running Clearance to check for proper clutch assembly in Specifications.

72. Install new seal rings (23) and (24) on forward low clutch piston (20).

73. Install piston (20) in the clutch housing. Install three seal rings (22) on shaft (21)

74. Install spring (19) and spring retainer (18).

75. Put the forward low clutch group in position in a press. Use tool (C) and compress the spring. Install retainer ring (17).

76. Lower the temperature of bearing assembly (16) and install it in hub (13).

77. Install thrust washer (15).

78. Install plates and discs (14). Install hub (13). Install retainer ring (12) with tool (B).

79. Install gear (11). Install retainer ring (10) with tool (A).

80. Install thrust washer (9) at the low end of the clutch group.

81. Install retainer ring (8) with tool (A).

NOTE: This completes the assembly of the forward low clutch group.

NOTE: See Procedure To Measure Running Clearance to check for proper clutch assembly in Specifications.

82. Fasten tool (G) to the forward low and high clutch group (7) and then put the clutch group in position in transmission housing (4).

NOTE: Use tool (J) to install shaft plugs (X) into the shafts.

83. Lower the temperature of race (6) and three bearings and install them in housing (2) with tooling (D).

84. Fasten tooling (F) and a hoist to the torque converter housing.

85. Install housing (2) and torque converter (5) on housing (4).

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NOTICE

During the assembly of the housings (2) and (4), be sure the clutch groups and the input shaft properly engages their respective bores or bearings. Do not force the housings together with the bolts or damage to the housings could be the result.