GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2001 🢒 Chevy C Cab/Chassis HD (GMT 400) 🢒 Transmission/Transaxle 🢒 Automatic Transmission - 4L80-E 🢒 Transmission Replacement

Removal Procedure
  1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Drain the transmission fluid. Refer to Automatic Transmission Fluid and Filter Replacement .
  3. Remove the transmission oil level indicator tube and seal from the transmission. Refer to Transmission Fluid Filler Tube and Seal Replacement .
  4. Plug the oil level indicator tube opening in the transmission.
  5. Remove the shift cable end from the transmission shift lever ball stud. Refer to Shift Cable Replacement .
  6. Remove the rear propeller shaft. Refer to Two-Piece Propeller Shaft Replacement or Three-Piece Propeller Shaft Replacement in Propeller Shaft.
  7. Remove the park brake drum. Refer to Propeller Shaft Parking Brake Drum Replacement in Park Brake.
  8. Remove the park brake cable from the bracket on the transmission. Refer to Park Brake Cable Replacement in Park Brake.
  9. Support the transmission with a suitable transmission jack.
  10. Remove the transmission support. Refer to Transmission Support Replacement in Frame and Underbody.
  11. Remove the necessary exhaust components to provide clearance when lowering the transmission. Refer to Catalytic Converter Replacement , Exhaust Manifold Pipe Replacement , or Exhaust Crossover Pipe Replacement in Engine Exhaust.
  12. Disconnect the transmission oil cooler lines from the transmission. Refer to Oil Cooler Hose/Pipe Replacement .
  13. Plug the transmission oil cooler line connectors in the transmission case.
  14. Remove the starter motor. Refer to Starter Motor Replacement in Engine Electrical.

    15. Object Number: 408374 Size: SH
  15. Remove the torque converter access plug.
  16. Remove the flywheel to torque converter bolts.

    17. Object Number: 394459 Size: SH
  17. Remove the two bolts securing the heat shield to the transmission.

    18. Object Number: 396800 Size: SH
  18. Remove the transmission vent hose, fuel lines, and the wiring harness from the transmission.

    19. Object Number: 394448 Size: SH
  19. Remove the stud and the bolt securing the transmission to the engine.

    20. Object Number: 394446 Size: SH
  20. Remove the six studs and one bolt securing the transmission to the engine.
  21. Install the J 21366 onto the transmission bell housing to retain the torque converter.
  22. Pull the transmission straight back.
  23. Remove the transmission from the vehicle.
  24. Flush the transmission oil cooler and cooling lines if necessary. Refer to Transmission Fluid Cooler Flushing and Flow Test .

Installation Procedure
  1. Install the J 21366 onto the transmission bell housing to retain the torque converter.
  2. Support the transmission with a transmission jack.
  3. Raise the transmission into place and remove the J 21366 from the transmission.
  4. Slide the transmission straight onto the locating pins while lining up the marks on the flywheel and the torque converter.

    5. Object Number: 394446 Size: SH

    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.

  5. Install six studs and one bolt securing the transmission to the engine.

    6. Tighten
    Tighten the studs and the bolt to 50 N·m (37 lb ft).


    Object Number: 394448 Size: SH
  6. Install the stud and bolt securing the transmission to the engine.

    7. Tighten
    Tighten the stud and the bolt to 50 N·m (37 lb ft).

  7. Install the flywheel to torque converter bolts.

    8. Object Number: 408374 Size: SH
  8. Install the torque converter access plug.

    9. Object Number: 396800 Size: SH
  9. Install the transmission vent hose, fuel lines, and the wiring harness to the transmission.

    10. Object Number: 394459 Size: SH
  10. Install the two bolts securing the heat shield to the transmission.

    11. Tighten
    Tighten the bolt to 17 N·m (13 lb ft).

  11. Install the starter motor. Refer to Starter Motor Replacement in Engine Electrical.
  12. Install the transmission support. Refer to Transmission Support Replacement in Frame and Underbody.
  13. Remove the transmission jack.
  14. Install the exhaust components. Refer to Catalytic Converter Replacement , Exhaust Manifold Pipe Replacement , or Exhaust Crossover Pipe Replacement in Engine Exhaust.
  15. Install the park brake cable to the bracket on the transmission. Refer to Park Brake Cable Replacement in Park Brake.
  16. Install the park brake drum. Refer to Propeller Shaft Parking Brake Drum Replacement in Park Brake.
  17. install the rear propeller shaft. Refer to Two-Piece Propeller Shaft Replacement or Three-Piece Propeller Shaft Replacement in Propeller Shaft.
  18. Install the shift cable end to the transmission shift lever. Refer to Shift Cable Replacement .
  19. Unplug the oil level indicator tube opening in the transmission.
  20. Install the transmission oil level indicator tube and seal to the transmission. Refer to Transmission Fluid Filler Tube and Seal Replacement .
  21. Connect the transmission oil cooler lines to the transmission. Refer to Oil Cooler Hose/Pipe Replacement .
  22. Lower the vehicle.
  23. Fill the transmission to the proper level with DEXRON® III transmission Fluid. Refer to Transmission Fluid Check .