Tools Required

Important: During assembly, lubricate the bearings and the parts that slide or mate together with Synthetic Manual Transmission Fluid GM P/N 12346190.

1. Install the 1st speed gear bearing and the 1st speed gear.
2. Install the reverse gear clutch gear and the synchronizer ring. Ensure that the synchronizer ring teeth face down toward the mainshaft shoulder.
3. Install the reverse gear clutch gear retainer ring.



4. Install the reverse bearing spacer and the bearing.



5. Install the reverse gear and the synchronizer assembly. Rotate the assembly until the gear drops into the fully seated position. If the synchronizer assembly was disassembled, the synchronizer sleeve must be reinstalled with the taper of the sleeve towards the reverse gear.



6. Install the reverse gear thrust washer.
7. Install the rear mainshaft bearing. Use a hydraulic press and theJ 22828 .
8. Turn the mainshaft over.



9. Install the following parts:

9.1.	The 1st speed gear clutch gear

9.2.	The clutch gear snap ring

9.3.	The synchronizer rings




10. Install the 1st speed gear synchronizer ring retainer ring.



11. Install the 1st/2nd synchronizer assembly. Install the synchronizer with the taper side of the synchronizer sleeve towards 2nd speed gear.



12. Install the 1st/2nd synchronizer assembly retainer ring.



13. Install the 2nd speed gear synchronizer rings.



14. Install the 2nd speed gear synchronizer ring retainer ring.



15. Install the 2nd speed gear bearing.



16. Install the 2nd speed gear.



17. Install the following parts:

17.1.

The 2nd speed gear thrust washer retaining pin.

17.2.

The 2nd speed gear thrust washer (Be sure the thrust washer is seated on the gear and the retaining pin.)

17.3.

The 2nd speed gear thrust washer retainer ring.




18. Install the 3rd speed gear bearing spacer and the bearing.
19. Install the 3rd speed gear and the synchronizer assembly. Hold the unit together and press on as an assembly.



20. Install the main drive gear thrust bearing.
21. Install the 4th speed gear synchronizer ring.
22. Install the 4th speed gear clutch gear.



23. Install the following parts:

23.1.

The overdrive speed gear shift lever

23.2.

The shift lever shaft (The notches that retain the overdrive speed gear shift fork are to the outside of the case.)

23.3.

The shift lever retaining pin




24. Install a rubber band in order to hold the overdrive speed gear shift lever back out of the way.



25. Install the countershaft front bearing cup. Use the J 38856 .



26. Install the countershaft assembly into the transmission case. Position the rear of the countershaft into the rear countershaft bearing bore than move the front of the countershaft into position.



27. Install the countershaft rear bearing using the following procedure:

27.1.

Position the transmission case with the front of the case down.

27.2.

Lift the countershaft and place a block of wood between the front of the countershaft and the transmission case.

27.3.

Using the J 22828 , install the countershaft rear bearing.




28. Install the following parts:

28.1.

The reverse idler gear

28.2.

The bearings

28.3.

The spacer

28.4.

The washers

28.5.

The reverse idler gear shaft (The step on the shaft aligns towards the countershaft and installed flush to the case.)




29. Position the transmission with the front of the case down.
30. Position the countershaft in the countershaft front bearing cup.
31. Install the countershaft rear bearing cup.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

32. Temporarily install the countershaft bearing retainer and the bolts.

Tighten
Tighten the countershaft bearing retainer bolts to 35 N·m (26 lb ft).




33. Measure the countershaft end play. Use the following procedure:

33.1.

Using a magnetic indicator base J 26900-13 (2) set the dial indicator J 8001 (1) on the end of the countershaft.

33.2.

Zero out the dial indicator.

33.3.

Using a screwdriver or the equivalent lift the countershaft and record the measurement.

The countershaft end play should be 0.05-0.15 mm (0.002-0.006 in).

33.4.

Remove the countershaft rear bearing retainer and bolts.

33.5.

Add shim(s) under the bearing retainer to achieve the correct end play.




34. Apply threadlocker GM P/N 12345493 to the countershaft retainer bolts.
35. Install the countershaft bearing retainer and bolts.

Tighten
Tighten the countershaft bearing retainer bolts to 35 N·m (26 lb ft).




36. Using the J 38856 with the J 8092 , install a NEW front countershaft bearing cap. When properly installed, the outer lip of the cap will be flush with case.



37. Install the mainshaft assembly into the transmission case.



38. If removed install a new input shaft bearing cone using the J 22828 (1) onto the input shaft.



39. Install the main drive gear bearing and the input shaft into the transmission case.



40. If removed, install a new input shaft bearing cup in the input shaft retainer.



41. Using the J 38801 , install the main drive gear seal into the input shaft retainer.



42. Apply a thin layer of RTV sealer GM P/N 12345739 or the equivalent to the input shaft retainer mating surface. Excessive amounts could plug the bearing oil passage.



43. Install the input shaft retainer. Position the retainer with the oil hole at the top-center position.
44. Apply threadlocker GM P/N 12345493 to the input shaft retainer bolts.
45. Install the input shaft retainer bolts.

Tighten
Tighten the input shaft retainer bolts to 31 N·m (23 lb ft).




46. Install the mainshaft rear bearing cup.
47. Temporarily install the mainshaft rear bearing retainer and bolts.

Tighten
Tighten the mainshaft rear bearing retainer bolts finger tight only.




48. Measure the countershaft end play. Use the following procedure:

48.1.

Using a magnetic indicator base J 26900-13 (2) set the dial indicator J 8001 (1) on the end of the mainshaft.

48.2.

Zero out the dial indicator.

48.3.

Using a screwdriver or the equivalent lift the mainshaft and record the measurement.

The mainshaft end play should be 0.05-0.15 mm (0.002-0.006 in).

48.4.

Remove the mainshaft rear bearing retainer and bolts.

48.5.

Add shim(s) under the bearing retainer to achieve the correct end play.




49. Apply threadlocker GM P/N 12345493 to the mainshaft rear bearing retainer bolts.
50. Install the mainshaft rear bearing retainer and bolts.

Tighten
Tighten the mainshaft rear bearing retainer bolts to 35 N·m (26 lb ft).




51. Install the following parts:

51.1.

The countershaft thrust washer retainer pin

51.2.

The countershaft thrust washer

51.3.

The overdrive speed gear bearings

51.4.

The spacer




52. Install the overdrive speed gear assembly onto the overdrive speed shift shaft and the countershaft. Slide overdrive speed gear fork and the overdrive speed gear assembly onto the shift shaft.



53. Install the overdrive speed gear clutch gear retainer ring.



54. Install the overdrive speed gear shift fork roll pins. Support the fork and drive the roll pins downward from the top of the fork.



55. (RWD models) Install the mainshaft overdrive gear on the mainshaft.
56. (RWD models) Install the vehicle speed sensor reluctor wheel on the mainshaft.



57. (4WD models) Using the J 38805 (1), install the a NEW mainshaft washer and the nut.

Tighten
Tighten the mainshaft nut to 540 N·m (400 lb ft).




58. (RWD models) Install the speedometer drive spacer, if equipped.
59. (RWD models) Using J 38807 and J 8092 , install the rear output shaft rear bearing in the transmission extension.



60. (RWD models) Install the mainshaft rear bearing retainer ring.



61. Apply RTV sealer GM P/N 12345739 on the mating surfaces of the transmission extension.
62. (4WD models) Install the transmission extension to the transmission case .

Tighten
Tighten the bolts to 54 N·m (40 lb ft).




63. (RWD models) Install the transmission extension to the transmission case.

Tighten
Tighten the bolts to 54 N·m (40 lb ft).




64. (RWD models) Using the J 22834-A , install a new mainshaft seal in the transmission extension.



65. (RWD models) Install the yoke assembly .
66. (RWD models) Install a NEW spline seal, a NEW washer, and the nut.
67. Shift the transmission into 1st gear to aid the tightening of the yoke nut.

Tighten
Tighten the yoke nut to 441 N·m (325 lb ft).

68. Fill the transmission to the proper level with Synthetic Manual Transmission Fluid GM P/N 12346190.



69. Apply RTV sealer GM P/N 12345739 or the equivalent to the mating surfaces of the transmission cover.



70. Install the shift cover to the transmission case.
71. Install the shift cover bolts and the brackets to their original location.

Tighten
Tighten the bolts to 27 N·m (20 lb ft).




72. Apply RTV sealer GM P/N 12345739 or the equivalent to the shift cover side of the shift tower isolator plate.



73. Install the shift tower isolator plate to the shift cover.
74. Install the shift tower to the isolator plate.
75. Install the shift tower to shift cover bolts.

Tighten
Tighten the bolts to 11 N·m (97 lb in).