Tools Required

1. Install the mainshaft front bearing in the input shaft.
2. Pack the bearing with J 36850 .



3. Install the input shaft on the J 41663 .
4. Install the assembled mainshaft onto the J 41663 .
5. Install the countershaft onto the J 41663 .
6. Install the reverse idler shaft assembly onto the J 41663 .
7. Install the 5th/reverse shift fork onto the 1st/2nd shift fork.
8. Install the fork assemblies onto the 1st/2nd and 5th/reverse gear sleeves.



9. Install the main shaft bearing retainer onto the mainshaft and the countershaft.

•	Ensure the fork end of the main shaft bearing retainer is installed under the countershaft rear bearing.

•	Ensure the hook end of the main shaft bearing retainer is installed under the mainshaft rear bearing.




10. Install the rear case over the mainshaft, countershaft and reverse idler shaft assembly.




Important: Two bolts of different length are used to secure the reverse idler shaft retainer and collar to the rear case. The forward (front) reverse idler shaft assembly hole houses the short bolt.

11. Install the 2 bolts that secure the reverse idler shaft assembly to the rear case.
12. Finger tighten the 2 bolts. If the rear bolt will not install all the way, inspect the alignment of the idler shaft hole to the idler shaft support collar.




Important: Use new O-rings with the 5 main shaft bearing retainer to case bolts.

13. Install the NEW O-rings on the 5 main shaft to bearing retainer bolts.

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.

14. Install the 5 main shaft bearing bolts using the following sequence:

14.1.

Finger start bolts 1, 2, and 4.

14.2.

Finger start bolts 3 and 5.

14.3.

Finger tighten the bolts in the following order:

1, 2, 3, 4, 5.

14.4.

Tighten the main shaft bearing retainer to housing bolts in the following order:

1, 2, 3, 4, 5.

Tighten
Tighten the bolts to 22 N·m (16 lb ft).

14.5.

Re-tighten the main shaft bearing retainer to housing bolts in the following order:

1, 2, 3, 4, 5.

Tighten
Tighten the bolts to 22 N·m (16 lb ft).

15. Tighten the reverse idler shaft assembly to case bolts.

Tighten

1. Tighten the reverse idler shaft assembly to case rear bolt to 22 N·m (16 lb ft).
2. Tighten the reverse idler shaft assembly to case forward bolt to 44 N·m (33 lb ft).
16. Remove the rear case assembly from the J 41663 .

Place the rear case assembly horizontally.




17. Install the 3rd/4th shift fork onto the 3rd/4th synchronizer sleeve.



18. Install the shift shaft into the 3rd/4th shift fork.
19. Install the shift shaft into the shift shaft lever and the shift rail bushing.
20. Install the shift shaft (1) through the 1st/2nd shift fork (5) and 5th/reverse shift fork (4).
21. Slide the shift shaft into the case.
22. Install the shift socket (2) onto the shift shaft.



23. Install the 30 mm (1.18 in) shift shaft lever roll pin into the shift shaft lever.

Ensure the roll pin to set flush with the shift shaft lever assembly.

24. Install the shift shaft socket and the 22 mm (0.866 in) roll pin onto the shift shaft.

Ensure the shift shaft socket roll pin is flush with the shift shaft socket hole.




25. Install the front countershaft roller bearing onto the countershaft.

Ensure the small end of the countershaft bearing is toward the clutch housing.

26. Pack the front countershaft bearing race with J 36850 .
27. Apply a thin layer of gasket maker GM P/N 1052943 to the mating surfaces of the rear case and the clutch housing.
28. Install the clutch housing onto the rear case.
29. Install the 9 bolts securing the clutch housing to the rear case.

Tighten
Tighten the case bolts to 33 N·m (24 lb ft).




30. Install the shift shaft detent pin into the top of the clutch housing.

Install the shift shaft detent pin by hand in order to ensure the detent pin installs into the shift shaft lever and the shift rail bushing.

Tighten
Tighten the shift shaft detent pin to 33 N·m (24 lb ft).




31. Install the following components:

•	The shift shaft detent plunger  (1)

•	The spring (2)

•	The detent plug (3)




32. Install the retaining ring on the input shaft bearing.
33. Install the input shaft seal in the bearing retainer using the J 38801 .



34. Apply a thin layer of RTV sealer GM P/N 12345739 or equivalent to the mating surfaces of the input shaft bearing retainer.

Install the input shaft bearing retainer to the clutch housing.

35. Install the 5 bolts that secure the input shaft bearing retainer to the clutch housing.

Tighten
Tighten the input bearing retainer bolts to 29 N·m (21 lb ft).




36. Apply pipe sealant GM P/N 12346004 to the backup lamp switch threads.
37. Install the backup lamp into the rear housing.

Tighten
Tighten the backup lamp to 37 N·m (28 lb ft).

38. Install the vehicle speed sensor.

Tighten
Tighten the vehicle speed sensor to 17 N·m (12 lb ft).

39. In order to prevent spillage, fill the transmission with oil after installing. Refer to Lubrication Specifications .



40. Apply pipe sealant GM P/N 12346004 to the oil fill plug threads.
41. Using the J 36511 , install the oil fill plug into the rear housing.

Tighten
Tighten the oil fill plug to 30 N·m (22 lb ft).