For 1990-2009 cars

### Installation Procedure

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.

1. Install the following items into the extension case:

• | Two select guide pins (3).

• | Two select return springs (2).

• | Two select return spring bolts (1).

Tighten
Tighten the return spring bolts to 20 N·m (15 lb ft).

2. Apply GM P/N 12346240 or equivalent to the transmission extension case mating surface.
3. Install the extension case (4) to the transmission; secure with twelve bolts.

Tighten
Tighten the extension case bolts to 28 N·m (20 lb ft).

4. Apply the GM P/N 12346240, or equivalent to the extension case gearshift lever case mating surface.
5. Install the gearshift lever case to the extension case; secure with ten bolts.

Tighten
Tighten the gearshift lever case bolts to 17 N·m (12 lb ft).

6. Install the breather hose to the gearshift lever case; secure with one clamp.
7. Raise the transmission slowly until the engine is no longer in contact with the wood block between the bulkhead (2) and the distributor gear housing.
8. Remove the wood block.
9. Install the rear transmission mount to the extension case; secure with one bolt.

Tighten
Tighten the rear transmission mount bolt to 60 N·m (44 lb ft).

10. Install the rear transmission crossmember to the vehicle; secure with four bolts.

Tighten
Tighten the rear transmission crossmember bolts to 60 N·m (44 lb ft).

11. Install the two bolts to the rear transmission mount (2).

Tighten
Tighten the rear transmission mount bolts to 60 N·m (44 lb ft).

12. Remove the hydraulic jack from underneath the transmission.
13. Install the Three Way Catalytic Converter (TWC) and the muffler/tail assembly to the vehicle.
14. Install the speedometer driven gear case and the ground wire (1) to the extension case (4); secure with one bolt (2).

Tighten
Tighten the speedometer driven gear case retaining bolt to 12 N·m (106 lb in).

15. Install the speedometer cable (3) to the speedometer driven gear case.
16. Install the rear propeller shaft into the vehicle aligning the index marks made during the removal procedure; secure with four bolts and four nuts.

Tighten
Tighten the rear propeller shaft bolts and the nuts to 50 N·m (37 lb ft).

17. Apply the GM P/N 12346005, or equivalent, to the threaded portion of the transmission drain plug.
18. Install the transmission drain plug (3) into the transmission.

Tighten
Tighten the transmission drain plug to 28 N·m (20 lb ft).

19. Add approximately 1.5 liters (1.6 quarts) of synthetic 75W-90 GL4 lubricant, or equivalent into the transmission oil level/filler plug (2). Oil level should be even with the bottom of the transmission oil level/filler plug (2) hole.
20. Apply GM P/N 12346004, or equivalent, to the threaded portion of the transmission oil level/filler plug (2).
21. Install the transmission oil level/filler plug (2) into the transmission.

Tighten
Tighten the transmission oil level/filler plug (2) to 28 N·m (20 lb ft).

22. Lower the vehicle.
23. Install four bolts to the fan shroud at the radiator.

Tighten
Tighten the fan shroud bolts to 10 N·m (89 lb in).

24. Install the gearshift control lever into the gearshift lever case. Refer to Gearshift Control Lever Installation .