Service Procedure
Numbers in parenthesis refer to figures in this bulletin.
1. Remove transmission from vehicle and install torque converter holding strap J-21366. When removing transmission, follow procedures in appropriate truck service manual.
NOTICE:
For Steps 2-40, refer to the section of the 1992 Light Duty Truck Unit Repair Manual regarding 4L80-E or 4L80-EHD transmissions for detailed procedures and illustrations. Also, be certain to inspect components for cracks and other damage during disassembly and reassembly of transmission.
2. Drain fluid from transmission and dispose of properly.
3. Remove two speed sensors (22) and bolts (23) with 8 mm socket.
4. Mount transmission on bench fixture using J-3289-20 base, J-8763-02 holding fixture, and J-38655 adapter.
5. Remove converter assembly (1) after removing torque converter holding strap J-21366.
NOTICE:
Torque converter is extremely heavy (approximately 65 lbs.), personal injury may result.
6. Remove turbine shaft o-ring (2).
7. For C Trucks or G Vans equipped with transmission models AJP, AFP, MJP, MKP, MLP, MPP, HTP, & TSP remove six 15 mm case extension bolts (21), extension assembly (19), extension-to-case seal (15), sleeve output shaft yoke seal (682) and seal output shaft (683).
8. Remove 10 mm pan assembly bolts (27), remove pan (28 or 85 depending on model) and seal assembly (29).
NOTICE:
Seal assembly (29) will be reused.
9. Remove filter assembly (31) and filter neck seal assembly (32).
10. Disconnect wire harness assembly (34) at pass through connector in the case.
NOTICE:
Use precautions to protect electrical pins from damage. To prevent electrical connector distress, do not pry off connectors from electrical components.
11. Remove harness assembly with valve assembly complete.
12. Remove 21 valve body assembly bolts (35), manual detent spring and roller assembly (41), lube pipe (39), short lube pipe bolt (36), retainer (37), clamp (38), three wiring clips (33), indicator stop (43), control valve assembly (including accumulator housing) (44), six pressure switch bolts (76), pressure swtich assembly (40) and check balls (54).
NOTICE:
Do not use a magnet to remove check bags. Magnet could cause a check bag to become magnetized, causing metal particles to stick to check ball.
13. Remove valve-body-to-case gasket (48).
14. Remove manual valve (319) from control valve assembly to prevent damage io manual valve.
15. Remove front servo assembly (55-60).
16. Remove six 10 mm rear servo accumulator cover bolts (61), rear servo accumulator cover (62), rear servo accumulator gasket (63) and rear servo accumulator assembly (64-74).
17. Remove 13 mm pump assembly bolts (3), pump assembly (4), pump-to-case seal (5) and pump-cover-to-case gasket (6). Use J-37789 when removing pump assembly.
18. Remove complete overdrive unit (501-522).
19. Remove 4th clutch bolt (26) using 40t torx head socket. Bolt will not be reused.
20. Remove housing assembly (529).
21. Remove forward clutch assembly (602) using J-38358-A.
22. Remove thrust washer (612).
23. Remove direct clutch assembly (623) using J-38733.
24. Remove front band (628).
25. Remove snap ring (629), intermediate clutch backing plate (630) and clutch plates (631 & 632).
26. Remove center support bolt (25) using 3/8-12 torx head socket. Bolt will not be reused.
27. Remove snap ring center support (633) and gear unit assembly (634-671) using J-38868.
28. Disassemble gear unit and output assembly (634-671).
29. Install new seal rings (639) to new center support (640) using J-38735. Reuse piston (636), seals (637 & 638), spring & retainer assembly (635), and snap ring (634) using J-23927 and J-38734 and install to center support.
30. Install new rear internal gear (666) to main shaft (662) with snap ring (670).
31. Assemble gear unit and output assembly (634-671).
32. Install gear unit and output assembly (634-671) into case using J-38868 and also installing snap ring (633).
33. Align center support (640) using J-23093.
a. Locate J-23093 into center support direct clutch passage through case.
b. Apply pressure on J-23093, seating center support splines counterclockwise against case splines (push tool toward rear servo bore).
c. Install new center support bolt (25) using 3/8-12 point torx head socket and torque to 43 N-m (32 lb.ft.). DO NOT OVER TORQUE.
34. Install intermediate clutch plates (632 & 631), backing plate (630) and snap ring (629). Backing plate is to be installed flat side down. Align clutch plates using J-24396.
NOTICE:
Dip an clutch plates in Dexron II-E transmission fluid.
35. Install front band (628) and direct clutch assembly (623) using J-38733.
36. Install thrust washer.
37. Install forward clutch assembly (602) into case using J-38358-A.
38. Install 4th clutch assembly (529) into case and install new 4th clutch bolt (26).
39. Disassemble 4th clutch plates (525 & 526), backing plate (524) and snap ring (523) to ease installation of overdrive unit (Step 42).
40. Rotate transmission to horizontal position and torque 4th clutch bolt (26) to 15-17 N-m (11-13 lb.ft.). DO NOT OVER TORQUE.
41. Install complete overdrive unit (501-522) into case.
42. Install 4th clutch plate (525 & 526), backing plate (524) and snap ring (523).
NOTICE:
Install steel plates with narrow tang at "one o'clock" position.
43. Install new pump gasket (6), new pump seal (5) and pump assembly (4) to case (7) with new bolts (3). Torque bolts to 24 N-m (18 lb. ft.) with 13 mm socket.
44. Install turbine shaft o-ring (2) to turbine shaft (502).
45. Install front servo assembly (55-60).
46. Install rear servo accumulator spring (74), servo parts (64-73), new rear servo accumulator gasket (63), rear servo accumulator cover (62) and six 10 mm rear servo accumulator bolts (61) into case (7). Torque rear servo accumulator bolts to 24 N-m (18 lb.ft.).
47. Install check balls (54) in proper location.
NOTICE:
Do not use a magnet to install check balls. Magnet could cause a check ban to become magnetized and cause metal particles to stick to the bag.
48. Install new valve-body-to-case gasket (48).
49. Install manual valve (319) into valve body assembly.
50. Install valve body assembly/accumulator (44) and wiring harness assembly (34) onto case.
51. Make certain that 5 o-rings are attached to switch assembly.
52. Install spring and roller assembly (41) to valve body.
53. Install fluid indicator stop (43), wiring clips (33), lube pipe clamp (38) and lube pipe (39) to valve body. Long end of lube pipe (39) inserts into case (7) and short end inserts into valve body.
54. Install 21 valve body assembly bolts (35) and torque to 11 N-m (97 lb.in.) using a 10 mm socket. Be certain to torque bolts (35) in alphabetical sequence shown in illustration attached.
55. Install pressure switch assembly (40) with 6 pressure switch assembly bolts (76). Torque bolts (76) to 11 N-m (97 lb.in.) using a 8 mm socket.
Be certain to torque bolts in alphabetical sequence shown in illustration attached.
56. Install lube pipe clip (37) to valve body with short bolt (36) and torque to 11 N-m (97 lb.in.) using 10 mm socket.
57. Install wiring harness (34) to five or six connectors (if removed).
58. Install new filter assembly (31), filter neck seal assembly (32), reusable pan seal (29), pan (28 or 85 depending on model), and pan bolts (27). Torque pan bolts to 24 N-m (18 lb.ft.) using 10 mm socket.
59. For C Trucks or G Vans with transmission models AJP, AFP, MJP, MKP, MLP, MPP, HTP, or TSP, install new sleeve output shaft yoke seal (682) and new seal output shaft (683) onto output shaft. Also, install extension assembly (19), seal (15) and six bolts (21). Torque bolts to 34 N-m (25 lb.ft.) using 15 mm socket.
60. Install two speed sensors, bracket assemblies (22) and two bolts (23). Torque bolts to 11 N-m (97 lb.ft.) using 8 mm socket.
61. Install torque converter assembly (1) and install holding strap J-21366.
NOTICE:
Torque converter is extremely heavy (approximately 65 lbs.), personal injury may result.
62. Remove transmission from bench fixture and install into vehicle.
63. Disconnect holding strap J-21366.
64. Install transmission into vehicle.
65. Fill transmission to proper level per cold check procedure.
66. Test drive vehicle.
67. Check transmission fluid and fill to proper level when transmission is at proper temperature.
68. Install Campaign Identification Label.