4L80-E/4L85-E - Automatic Transmission

Case Extension Assembly Replacement

Removal Procedure





1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle .
2. Support the transmission with a transmission jack.
3. Place a drain pan under the vehicle.
4. Remove the propeller shaft. Refer to One-Piece Propeller Shaft Replacement (One-Piece Propeller Shaft Replacement) or Two-Piece Propeller Shaft Replacement (Two-Piece Propeller Shaft Replacement) .
5. Remove the transmission support and the transmission mount. Refer to Transmission Mount Replacement (4L80-E/4L85-E - Automatic Transmission) .
6. Remove the case extension bolts (3).
7. Remove the case extension (1).
8. Remove and discard the case extension O-ring seal (2).



Installation Procedure





1. Install a new case extension O-ring seal (2).
2. Install the case extension (1).
Notice: Refer to Fastener Notice .


3. Install the case extension bolts (3).

Tighten the case extension bolts (3) to 34 N.m (25 lb ft).

4. Install the transmission support and the transmission mount. Refer to Transmission Mount Replacement (4L80-E/4L85-E - Automatic Transmission) .
5. Install the propeller shaft. Refer to One-Piece Propeller Shaft Replacement (One-Piece Propeller Shaft Replacement) or Two-Piece Propeller Shaft Replacement (Two-Piece Propeller Shaft Replacement) .
6. Remove the drain pan and the transmission jack.
7. Lower the vehicle.
8. Fill the transmission to the proper level with DEXRON(R) VI transmission fluid. Refer to Transmission Fluid Check (4L80-E/4L85-E Automatic Transmission) .