GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2009 🢒 Savana 🢒 Transmission 🢒 Automatic Transmission - 4L80-E/4L85-E 🢒 Case Extension Assembly Replacement

Removal Procedure

    Object Number: 747478 Size: SH
  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 or Two-Piece Propeller Shaft Replacement.
  5. Remove the transmission support and the transmission mount. Refer to Transmission Mount Replacement.
  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

    Object Number: 747478 Size: SH
  1. Install a new case extension O-ring seal (2).

    2. Caution: Refer to Fastener Caution in the Preface section.

  2. Install the case extension (1).
  3. Install the case extension bolts (3) and tighten to 34 N·m (25 lb ft).
  4. Install the transmission support and the transmission mount. Refer to Transmission Mount Replacement.
  5. Install the propeller shaft. Refer to One-Piece Propeller Shaft Replacement or 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® VI transmission fluid. Refer to Transmission Fluid Check.