GM Service Manual Online
For 1990-2009 cars only

Transmission Replacement LM4

Tools Required

J 21366 Converter Holding Strap

Removal Procedure

  1. Disconnect the battery. Refer to Battery Negative Cable Disconnection and Connection .
  2. Raise the vehicle. Refer to Lifting and Jacking the Vehicle .
  3. Drain the transmission fluid if necessary. Refer to Automatic Transmission Fluid and Filter Replacement .
  4. Remove the rear propeller shaft. Refer to Rear Propeller Shaft Replacement .
  5. Support the transmission with a transmission jack.

  6. Object Number: 744176  Size: SH
  7. Remove the nuts securing the transmission mount to the transmission support.

  8. Object Number: 752134  Size: SH
  9. Remove the transmission support from the vehicle. Refer to Transmission Support Replacement .

  10. Object Number: 899346  Size: SH
  11. Remove the transmission mount bolt (1).
  12. Remove the transmission mount from the vehicle.
  13. Remove the front exhaust pipe assembly. Refer to Catalytic Converter Replacement .
  14. Lower the transmission to gain access to the top and sides of the transmission.
  15. Remove the transfer case, if equipped. Refer to Transfer Case Assembly Replacement for the NVG 126-NP4 transfer case or Transfer Case Assembly Replacement for the 226-NP4 transfer case.

  16. Object Number: 744174  Size: SH
  17. Remove the range selector cable end from the transmission range selector lever ball stud (6) and the bracket (1). Refer to Range Selector Lever Cable Replacement .
  18. Remove the transmission heat shield. Refer to Transmission Heat Shield Replacement .
  19. Disconnect the transmission vent hose, the park/neutral position switch connectors, and the main electrical connector from the transmission. Refer to Park/Neutral Position Switch Replacement .
  20. Remove the transmission harness from the retainers.

  21. Object Number: 899344  Size: SH
  22. Remove the bolt that secures the fuel line bracket to the left side of the transmission.

  23. Object Number: 408374  Size: SH
  24. Remove the torque converter access plug.
  25. Mark the flywheel and torque converter orientation for reassembly.
  26. Remove the flywheel to torque converter bolts.
  27. Disconnect the transmission oil cooler lines from the transmission. Refer to Transmission Fluid Cooler Hose/Pipe Replacement .
  28. Plug the transmission oil cooler line connectors in the transmission case.
  29. Install a safety chain around the transmission.

  30. Object Number: 899345  Size: SH
  31. Remove the nut that secures the filler tube to the bell housing.
  32. Remove the transmission filler tube.

  33. Object Number: 899342  Size: SH
  34. Remove the remaining nuts, studs and/or bolts that secure the transmission to the engine.
  35. Install the J 21366 onto the transmission bell housing to retain the torque converter.
  36. Pull the transmission straight back.
  37. Remove the transmission from the vehicle.

Installation Procedure


    Object Number: 899342  Size: SH
  1. Install the J 21366 onto the transmission bell housing to retain the torque converter.
  2. Raise the transmission into place and remove the J 21366 from the transmission.
  3. Slide the transmission straight onto the locating pins while lining up the marks on the flywheel and the torque converter made during removal. The torque converter must be flush onto the flywheel and rotate freely by hand.
  4. Notice: Refer to Fastener Notice in the Preface section.

  5. Install nuts, studs and/or bolts securing the transmission to the engine.
  6. Tighten
    Tighten the studs and/or bolts to 50 N·m (37 lb ft).


    Object Number: 899344  Size: SH
  7. Install the fuel line retaining bracket to the transmission.

  8. Object Number: 408374  Size: SH
  9. Install the flywheel to torque converter bolts. Use care not to drop the bolts into the bell housing.
  10. Tighten
    Tighten the bolts to 60 N·m (44 lb ft).

  11. Install the torque converter access plug.
  12. Remove the safety chain from the transmission.

  13. Object Number: 899345  Size: SH
  14. Install the transmission filler tube.
  15. Install the filler tube nut.
  16. Tighten
    Tighten the filler tube nut to 10 N·m (7 lb ft).

  17. Install the transmission vent hose (2), fuel lines, and the wiring harness to the transmission.
  18. Install the transmission harness to the retainers.
  19. Install the heat shield to the transmission. Refer to Transmission Heat Shield Replacement .
  20. Install the bolts securing the heat shield to the transmission.
  21. Tighten
    Tighten the bolts to 17 N·m (13 lb ft).


    Object Number: 744174  Size: SH
  22. Install the shift cable end to the transmission shift lever ball stud (6) and bracket (1). Refer to Range Selector Lever Cable Replacement .
  23. Install the transfer case, if equipped. Refer to Transfer Case Assembly Replacement for the NVG 126-NP4 transfer case or Transfer Case Assembly Replacement for the 226-NP4 transfer case.
  24. Install the front exhaust pipe assembly. Refer to Catalytic Converter Replacement .

  25. Object Number: 899346  Size: SH
  26. Install the transmission mount to the vehicle.
  27. Install the bolts (1) securing the transmission mount to the transmission.
  28. Tighten
    Tighten the bolts to 25 N·m (18 lb ft).


    Object Number: 752134  Size: SH
  29. Install the transmission support to the vehicle. Refer to Transmission Support Replacement .

  30. Object Number: 744176  Size: SH
  31. Lower the transmission and remove the transmission jack.
  32. Install the nuts securing the transmission mount to the transmission support.
  33. Tighten
    Tighten the nuts to 46 N·m (35 lb ft).

  34. Install the rear propeller shaft. Refer to Rear Propeller Shaft Replacement .
  35. Flush the transmission oil cooler and cooling lines at this time, if necessary. Refer to Transmission Fluid Cooler Flushing and Flow Test .
  36. Connect the transmission oil cooler lines (4) to the transmission. Refer to Transmission Fluid Cooler Hose/Pipe Replacement .
  37. Lower the vehicle.
  38. Connect the battery. Refer to Battery Negative Cable Disconnection and Connection .
  39. Fill the transmission to the proper level with DEXRON® VI transmission fluid and check for leaks. Refer to Transmission Fluid Check .
  40. Important: It is recommended that transmission adaptive pressure (TAP) information be reset.

    Resetting the TAP values using a scan tool will erase all learned values in all cells. As a result, the engine control module (ECM), powertrain control module (PCM) or transmission control module (TCM) will need to relearn TAP values. Transmission performance may be affected as new TAP values are learned.

  41. Reset the TAP values. Refer to Transmission Adaptive Functions .
  42. Road test the vehicle and check for proper operation.

Transmission Replacement LL8

Tools Required

J 21366 Converter Holding Strap

Removal Procedure

  1. Disconnect the battery. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.

  2. Object Number: 744648  Size: SH
  3. Remove the filler tube nut (2) located on the right side of the engine.
  4. Remove the filler tube from the stud (1) on the right side of the engine.
  5. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  6. Drain the transmission fluid if necessary. Refer to Automatic Transmission Fluid and Filter Replacement .
  7. If equipped with 2 wheel drive (2WD) Remove the rear propeller shaft. Refer to Rear Propeller Shaft Replacement in Propeller Shaft.
  8. If equipped with 4 wheel drive (4WD) Remove the transfer case. Refer to Transfer Case Assembly Replacement in Transfer Case - NVG 126-NP4 or Transfer Case Assembly Replacement in Transfer Case - NVG 226-NP8 depending on the model of transfer case the vehicle is equipped with.
  9. Support the transmission with a transmission jack.
  10. Remove the fuel tank shield if equipped. Refer to Fuel Tank Shield Replacement in Frame and Underbody.

  11. Object Number: 752134  Size: SH
  12. Remove the transmission support. Refer to Transmission Support Replacement in Frame and Underbody.

  13. Object Number: 1334965  Size: SH
  14. Remove the transmission mount. Refer to Transmission Mount Replacement .

  15. Object Number: 753684  Size: SH
  16. Remove the catalytic converter assembly. Refer to Catalytic Converter Replacement in Engine Exhaust.
  17. Lower the transmission to gain access to the top and sides of the transmission.

  18. Object Number: 744174  Size: SH
  19. Remove the range selector cable end from the transmission range selector lever ball stud (6) and the bracket (1). Refer to Range Selector Lever Cable Replacement .
  20. Remove the transmission heat shield. Refer to Transmission Heat Shield Replacement .

  21. Object Number: 744644  Size: SH
  22. Disconnect the transmission vent hose from the transmission.

  23. Object Number: 173661  Size: SH
  24. Disconnect the main electrical connector from the transmission.
  25. Disconnect the park/neutral position switch connector. Refer to Park/Neutral Position Switch Replacement .

  26. Object Number: 730721  Size: SH
  27. Remove the bolt that secures the fuel line bracket to the left side of the transmission.

  28. Object Number: 744183  Size: SH
  29. Remove the torque converter access plug.
  30. Mark the flywheel and torque converter orientation for reassembly.
  31. Remove the flywheel to torque converter bolts. Use care not to drop the bolts into the bell housing.
  32. Disconnect the transmission oil cooler lines from the transmission. Refer to Transmission Fluid Cooler Hose/Pipe Replacement .
  33. Plug the transmission oil cooler line connectors in the transmission case.

  34. Object Number: 727335  Size: SH
  35. Remove the bolt that secures the fuel line bracket to the bell housing.

  36. Object Number: 744272  Size: SH
  37. Remove the bolts (1,2) that secure the coolant pipe to the bell housing.
  38. Install a safety chain around the transmission.

  39. Object Number: 727330  Size: SH
  40. Remove the remaining nuts, studs and/or bolts that secure the transmission to the engine.
  41. Install the J 21366 onto the transmission bell housing to retain the torque converter.
  42. Pull the transmission straight back to clear the torque converter.
  43. Lower the transmission away from the vehicle.

Installation Procedure

  1. Install the J 21366 onto the transmission bell housing to retain the torque converter.
  2. Raise the transmission into place and remove the J 21366 from the transmission.

  3. Object Number: 727330  Size: SH
  4. Slide the transmission straight onto the locating pins while lining up the marks on the flywheel and the torque converter made during removal. The torque converter must be flush onto the flywheel and rotate freely by hand.
  5. 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.

  6. Install nuts, studs and/or bolts securing the transmission to the engine.
  7. Tighten
    Tighten the studs and/or bolts to 50 N·m (37 lb ft).


    Object Number: 744183  Size: SH
  8. Install the flywheel to torque converter bolts. Use care not to drop the bolts into the bell housing.
  9. Tighten
    Tighten the bolts to 60 N·m (44 lb ft).

  10. Install the torque converter access plug.
  11. Remove the safety chain from the transmission.

  12. Object Number: 730721  Size: SH
  13. Install the bolt that secures the fuel line bracket to the left side of the transmission.

  14. Object Number: 173661  Size: SH
  15. Connect the main electrical connector to the transmission.
  16. Connect the park/neutral position switch connector. Refer to Park/Neutral Position Switch Replacement .

  17. Object Number: 744644  Size: SH
  18. Connect the transmission vent hose to the transmission.
  19. Install the transmission heat shield. Refer to Transmission Heat Shield Replacement .

  20. Object Number: 744174  Size: SH
  21. Install the range selector cable end to the transmission range selector ball stud (6) and the bracket (1). Refer to Range Selector Lever Cable Replacement .
  22. Raise the transmission to the normal installed height.

  23. Object Number: 753684  Size: SH
  24. Install the catalytic converter assembly. Refer to Catalytic Converter Replacement in Engine Exhaust.

  25. Object Number: 1334965  Size: SH
  26. Install the transmission mount. Refer to Transmission Mount Replacement .

  27. Object Number: 752134  Size: SH
  28. Install the transmission support. Refer to Transmission Support Replacement in Frame and Underbody.
  29. Remove the transmission jack.
  30. Install the fuel tank shield if equipped. Refer to Fuel Tank Shield Replacement .
  31. If equipped with 4WD install the transfer case. Refer to Transfer Case Assembly Replacement in Transfer Case - NVG 126-NP4 or Transfer Case Assembly Replacement in Transfer Case - NVG 226-NP8 depending on the model of transfer case the vehicle is equipped with.
  32. If equipped with 2WD install the rear propeller shaft. Refer to Rear Propeller Shaft Replacement in Propeller Shaft.

  33. Object Number: 744636  Size: SH
  34. Flush the transmission oil cooler and cooling lines at this time, if necessary. Refer to Transmission Fluid Cooler Flushing and Flow Test .
  35. Connect the transmission oil cooler lines (4) to the transmission. Refer to Transmission Fluid Cooler Hose/Pipe Replacement .
  36. Lower the vehicle.

  37. Object Number: 744648  Size: SH
  38. Install the filler tube to the stud (1) on the right side of the engine.
  39. Install the filler tube nut (2).
  40. Tighten
    Tighten the nut to 10 N·m (7 lb ft).

  41. Connect the battery. Refer to Battery Negative Cable Disconnection and Connection .
  42. Fill the transmission to the proper level with DEXRON® III transmission fluid and check for leaks. Refer to Transmission Fluid Check .
  43. Road test the vehicle and check for proper operation.