For 1990-2009 cars

#### Tools Required

• | J 8092 Universal Driver

• | J 25070 Heat Gun - 500-750 F

• | J 44741 Shift Rail Bearing Installer

• | J 44742 Bearing Installer

1. Using the J 25070 , heat the front case for 10-15 minutes.

Important: With the rear case still hot, install the bearing races. Do not allow the rear case to cool.

2. Install the shift rail bearing, with the part number up, in the rear case using the J 8092 (1) and the J 44741 (2). The J 44741 (2) will install the bearing to the proper depth.
3. Install the countershaft rear bearing in the rear case using the J 8092 (1) and the J 44742 (2).
4. Lightly lubricate the reverse idler gear, bearings and shaft with GM P/N 12378515 (Canadian P/N 88900701).
5. Install the reverse idler gear in the rear case. The oil grooves on the reverse gear align to the case, or to the output end of the case.
6. Install the reverse gear idler bearings in the reverse gear.
7. Install the reverse gear idler shaft.

• | The bolt hole end is up.

• | Use the bracket bolt to align the shaft bolt hole with the bolt hole in the case.

8. Install the reverse gear idler shaft bracket.

• | The part numbers on the bracket align away from the case, or up.

• | Align the bracket bolt hole with the case.

• | The bracket will drop in place if squarely set to the case.

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.

9. Install the reverse gear idler shaft bracket bolt with a new O-ring seal.

Tighten
Tighten the reverse idler gear bracket bolt to 23 N·m (17 lb ft).

10. Apply pipe sealant GM P/N 12346004 (Canadian P/N 10953480) to the threads of the back-up lamp switch.
11. Install the back-up lamp switch in the rear case.

Tighten
Tighten the back up lamp switch to 20 N·m (15 lb ft).

12. If 4WD, lightly lubricate the mainshaft rear bearing O-ring seal with transmission lubricant GM P/N 12378515 (Canadian P/N 88900701).
13. Install the mainshaft rear bearing O-ring seal in the rear case.