Forward and Coast Clutch Assembly Overhaul

Tools Required

• J 39055  Forward Clutch Inner Seal Protector. See Special Tools .
• J 39056  Coast Clutch Seal Protector. See Special Tools .
• J 23327  Clutch Spring Compressor
• J 28585  Snap Ring Remover. See Special Tools .

Fig 1: Parking Lock Gear And The Thrust Bearing And Snap Ring
Courtesy of GENERAL MOTORS CORP.
1. Using the J 28585  , remove the snap ring (834) from the final drive sun gear shaft. See Special Tools .
2. Remove the parking lock gear (833) and the thrust bearing (832).
Fig 2: Locating Low Roller Clutch Assembly, Forward And Coast Clutch Support & Thrust Bearing
Courtesy of GENERAL MOTORS CORP.
3. Remove the forward and coast clutch support with the low roller clutch assembly (822-830).
4. Remove the thrust bearing (417).
Fig 3: Identifying Forward And Coast Clutch Housing
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5. Lift the forward and coast clutch housing (801) off of the coast clutch hub.
6. Remove the thrust bearing (718) from the forward coast clutch housing (801).
Fig 4: Identifying Input Carrier From Input Internal Gear And Flange
Courtesy of GENERAL MOTORS CORP.
7. Separate the input carrier (708) from the input internal gear and flange.
Fig 5: Identifying Input Carrier Assembly & Thrust Bearing
Courtesy of GENERAL MOTORS CORP.
8. Lift the input carrier assembly (700-708) off of the final drive sun gear shaft (722).
9. Remove the thrust bearing (710) from the input carrier assembly (700-708).
Fig 6: View Of Input Carrier Assembly, Reaction Internal Gear & Snap Ring
Courtesy of GENERAL MOTORS CORP.
10. Remove the snap ring (709) in order to separate the input carrier (700) from the reaction internal gear (708). The thrust bearing will stay inside of the input carrier (700).
Fig 7: Inspecting Input Carrier Pinions, Reaction Internal Gear & Snap Ring For Damage
Courtesy of GENERAL MOTORS CORP.
11. Inspect the snap ring (709) for burrs or damage.
12. Inspect the input carrier (700) pinions for nicked or broken teeth.
13. Inspect the input carrier internal gear 708) for broken teeth.
Fig 8: Measuring Input Carrier End Play With Feeler Gage
Courtesy of GENERAL MOTORS CORP.
14. With a feeler gauge, measure the input carrier (700) end play. The end play should be within a range of 0.09-0.90 mm (0.003-0.035 in).
Fig 9: View Of Input Carrier Assembly, Reaction Internal Gear & Snap Ring
Courtesy of GENERAL MOTORS CORP.
15. Place the input carrier assembly (700) into the reaction internal gear (708).
16. Install the snap ring (709).
Fig 10: Identifying Input Carrier And Reaction Internal Gear Assembly Thrust Bearing
Courtesy of GENERAL MOTORS CORP.
17. Install the thrust bearing (710) onto the input carrier and reaction internal gear assembly.
Fig 11: View Of Thrust Washer On Coast Clutch Hub, Input Internal Gear Flange And Snap Ring
Courtesy of GENERAL MOTORS CORP.
18. Remove the following parts:
    • The input internal gear snap ring (717)
    • The coast clutch hub (719)
    • The thrust washer (720)
Fig 12: View Of Forward Sprag, Thrust Washer And Input Internal Gear Flange
Courtesy of GENERAL MOTORS CORP.
19. Remove the forward sprag outer race (721) and forward sprag from the input internal gear flange (708/725). Remove the thrust washer (713).
Fig 13: Locating Input Internal Gear, Snap Ring And Input Internal Gear Flange
Courtesy of GENERAL MOTORS CORP.
20. Remove the snap ring (709) from the input internal gear (708).
21. Lift the input internal gear flange (725) from the input internal gear (708).
Fig 14: View Of Input Internal Gear Flange & Bushing Inspection Areas
Courtesy of GENERAL MOTORS CORP.
22. Inspect the input internal gear flange (725) for broken teeth. Inspect the input internal gear flange bushing.
23. Inspect the input internal gear (708) for nicked or broken teeth.
Fig 15: Locating Input Internal Gear, Snap Ring And Input Internal Gear Flange
Courtesy of GENERAL MOTORS CORP.
24. Install the input internal gear flange (725) into the input internal gear (708).
25. Install the input internal gear snap ring (709).
Fig 16: View Of Forward Sprag Clutch
Courtesy of GENERAL MOTORS CORP.
26. Remove the forward sprag outer race (721).
27. Disassemble the forward sprag clutch (716).
28. Inspect the forward sprag (716) for the following:
    • Damage or burrs
    • Damage to the inner side of the race
Fig 17: View Of Forward Sprag Clutch
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: Oil feed holes in the forward sprag outer race must face the input internal gear.
IMPORTANT: The lip on the forward sprag cage must face the input internal gear.
29. Assemble the forward sprag clutch (716).
30. Install the forward sprag clutch (716) into the forward sprag outer race (721).
Fig 18: View Of Forward Sprag, Thrust Washer And Input Internal Gear Flange
Courtesy of GENERAL MOTORS CORP.
31. Install the thrust washer (713) onto the input internal gear flange (708/725).
32. Install the forward sprag and outer race (721) onto the input internal gear flange (708/725).
Fig 19: Checking Forward Sprag Rotation
Courtesy of GENERAL MOTORS CORP.
33. Check that the forward sprag rotation freewheels in a counterclockwise direction.
Fig 20: View Of Thrust Washer On Coast Clutch Hub, Input Internal Gear Flange And Snap Ring
Courtesy of GENERAL MOTORS CORP.
34. Install the thrust washer (720) onto the coast clutch hub (719).
35. Install the coast clutch hub (719) onto the input internal gear flange (708).
36. Install the snap ring (717) onto the input internal gear flange (708).
Fig 21: Identifying Thrust Bearing And Coast Clutch Hub
Courtesy of GENERAL MOTORS CORP.
37. Install the thrust bearing (718) onto the coast clutch hub.
Fig 22: Identifying Forward Clutch Plates
Courtesy of GENERAL MOTORS CORP.
38. Remove the forward and coast clutch housing snap ring (818).
39. Remove the forward and coast clutch backing plate (819), and all of the forward clutch fiber (817) and steel (816) plates. Remove the apply plate (840).
Fig 23: Locating Coast Clutch Plates
Courtesy of GENERAL MOTORS CORP.
40. Remove the forward and coast clutch belleville plate (841) and backing plate (840).
41. Remove the coast clutch fiber (814) and steel (813) plates. Remove the apply plate (812).
Fig 24: Compressing Spring And Retainer Assembly Using The J 23327
Courtesy of GENERAL MOTORS CORP.
42. Using the J 23327  , compress the spring and retainer assembly (820).
IMPORTANT: Do not overexpand the snap ring.
43. Remove the snap ring (821).
44. Remove the J 23327  .
45. Remove the spring and retainer assembly (820).
Fig 25: Identifying Coast Clutch Piston Assembly
Courtesy of GENERAL MOTORS CORP.
46. Remove the coast clutch piston assembly (810).
47. Remove the apply ring (811). Remove the forward clutch piston and seals assembly (807).
Fig 26: Identifying Inspection Areas On Forward And Coast Clutch Housing
Courtesy of GENERAL MOTORS CORP.
48. Inspect the forward and coast clutch housing (801) for the following:
    • Feed passages that are plugged
    • Splines that are worn or damaged
    • Checkball for leaks
    • Welds for cracks
    • Bushings for excessive wear
Fig 27: View Of Forward Clutch Piston Seals Inspection Areas
Courtesy of GENERAL MOTORS CORP.
49. Inspect the forward clutch piston seals (808, 809) for damage. If the seals are damaged, replace the piston.
50. Inspect the forward clutch piston for cracks or damage to the seal grooves.
Fig 28: Installing The Forward Clutch Piston (807) Into The Forward And Coast Clutch Housing Using J 39055
Courtesy of GENERAL MOTORS CORP.
51. Install the new piston seals onto the forward clutch piston (807). Make sure that the outer seal does not roll backwards.
52. Using the J 39055  , install the forward clutch piston (807) into the forward and coast clutch housing (801). See Special Tools .
53. Remove the J 39055  . See Special Tools .
Fig 29: Inspecting Coast Clutch Piston Assembly
Courtesy of GENERAL MOTORS CORP.
54. Inspect the snap ring (821) for damage.
55. Inspect the spring and retainer assembly (820) for a damaged cage and distorted or missing springs.
56. Inspect the coast clutch piston assembly (810) for damage.
57. Inspect the apply ring (811) for damage.
Fig 30: Identifying Coast Clutch Piston Assembly And Coast Clutch Housing
Courtesy of GENERAL MOTORS CORP.
58. Install the apply ring (811) into the forward and coast clutch housing (801).
59. Using the J 39056  , install the coast clutch piston assembly into the coast clutch housing. See Special Tools . Make sure that the outer seal does not roll backwards.
60. Remove the J 39056  . See Special Tools .
Fig 31: Compressing Spring And Retainer Assembly Into Forward And Coast Clutch Housing Using J 23327
Courtesy of GENERAL MOTORS CORP.
61. Install the spring and retainer assembly (820) into the forward and coast clutch housing.
62. Using the J 23327  , compress the spring and retainer assembly (820). Install the snap ring (821).
63. Remove the J 23327  .
Fig 32: Locating Coast Clutch Plates
Courtesy of GENERAL MOTORS CORP.
64. Install the coast clutch apply plate (812) into the forward and coast clutch housing (801).
65. Install the coast clutch fiber (814) and steel (813) plates.
66. Install the forward and coast clutch plate (840), and the forward and coast clutch belleville plate (841).
Fig 33: Identifying Forward Clutch Plates
Courtesy of GENERAL MOTORS CORP.
67. Install the forward and coast clutch plate (840)
68. Install all of the forward clutch fiber (817) and steel (816) plates.
69. Install the forward clutch backing plate (819).
70. Install the snap ring (818).
Fig 34: Locating Coast Clutch Hub With The Thrust Bearing
Courtesy of GENERAL MOTORS CORP.
71. Install the coast clutch hub with the thrust bearing, the forward sprag race, and the input internal gear and flange into the forward and coast clutch housing.
Fig 35: Measuring Input Carrier And Reaction Internal Gear To Edge Of The Input Internal Gear
Courtesy of GENERAL MOTORS CORP.
72. When the splines on the hubs are properly engaged, the bushing on the input carrier will drop below the forward and coast clutch support hub, producing a dull metal sound. The distance from the top edge of the forward and coast clutch housing to the top edge of the input internal gear is approximately 22 mm (0.886 in).
Fig 36: Identifying Input Carrier And Reaction Internal Gear
Courtesy of GENERAL MOTORS CORP.
73. Install the input carrier and reaction internal gear with the thrust bearing onto the input internal gear.
Fig 37: View Of Low Roller Clutch Assembly
Courtesy of GENERAL MOTORS CORP.
74. Remove the low roller clutch assembly (830) from the forward and coast clutch support (822).
Fig 38: View Of Oil Seal Rings
Courtesy of GENERAL MOTORS CORP.
75. Remove the three oil seal rings (829) from the forward and coast clutch support (822).
76. Remove the cooler return seal (828).
Fig 39: Inspection Areas On Forward And Coast Clutch Support
Courtesy of GENERAL MOTORS CORP.
77. Inspect the forward and coast clutch support (822) for the following:
    • Damage to the seal ring grooves
    • Damage to the checkball
    • Damage and wear to the bushing and transfer sleeve
Fig 40: View Of Oil Seal Rings
Courtesy of GENERAL MOTORS CORP.
78. Install new oil seal rings (829).
IMPORTANT: Do not press the seal so that the shape of the seal is distorted in the bore.
79. Install a new cooler return seal (828) with the appropriate socket.
Fig 41: Aligning Low Roller Clutch Assembly
Courtesy of GENERAL MOTORS CORP.
80. Install the low roller clutch assembly (830) into the forward and coast clutch support (822). Turn the low roller clutch assembly (830) counterclockwise as far as it can go. The tabs on the low roller clutch assembly (830) must rest on the face of the forward and coast clutch support (822).
Fig 42: Identifying Forward And Coast Clutch Assembly Thrust Bearing
Courtesy of GENERAL MOTORS CORP.
81. Install the thrust bearing (417) onto the forward and coast clutch assembly.
82. Install the forward and coast clutch support and low roller clutch assembly (822/830) onto the forward and coast clutch assembly.
Fig 43: Checking Low Roller Clutch Assembly Rotation
Courtesy of GENERAL MOTORS CORP.
83. Check the rotation of the low roller clutch assembly. The low roller clutch assembly should freewheel in the counterclockwise direction.
Fig 44: Locating Final Drive Sun Gear Shaft
Courtesy of GENERAL MOTORS CORP.
84. Install the final drive sun gear shaft (722).
Fig 45: Identifying Parking Lock Gear And Final Drive Sun Gear Shaft Components
Courtesy of GENERAL MOTORS CORP.
85. Install the thrust bearing (832), the parking lock gear (833), and the snap ring (834) onto the final drive sun gear shaft (722).