GM Service Manual Online
For 1990-2009 cars only

Special Tools

    • J 25025-B Pump and Valve Body Alignment Pin Set
    • J 36850 Transjel Lubricant

Removal Procedure


    Object Number: 14464  Size: SH
  1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
  2. Remove the transmission oil pan and filter. Refer to Automatic Transmission Fluid and Filter Replacement.
  3. Note: The 1-2 accumulator can be removed without removing the control valve assembly.

  4. Remove the control valve body. Refer to Control Valve Body Replacement.
  5. Remove the accumulator cover retaining bolts.
  6. Remove the 1-2 accumulator cover assembly.
  7. Disassemble the 1-2 accumulator. Refer to 1-2 Accumulator Disassemble.

  8. Object Number: 1283236  Size: SH
  9. Remove the spacer plate support retaining bolts (77).
  10. Note: Use care not to drop the following items that will be removed along with the spacer plate:

       • The number 1 checkball
       • The 3-4 accumulator spring
       • The 3-4 accumulator pin

  11. Remove the spacer plate support (53 or 113).

  12. Object Number: 1887647  Size: SH

    Note: Do not reuse the bonded spacer plate. Replace with a NEW bonded spacer plate.

  13. Remove the bonded valve body spacer plate (48), discard, do not reuse.

  14. Object Number: 647519  Size: SH
  15. Remove the 3-4 accumulator piston (2).
  16. Note: Some models do not use a 3-4 accumulator spring.

  17. Inspect the 3-4 accumulator spring for cracks.

  18. Object Number: 1730059  Size: SH
  19. Remove the 3-4 accumulator piston seal (45) from the 3-4 accumulator piston (44).
  20. Inspect the 3-4 accumulator piston for the following defects:
  21. • Porosity
    • Cracks
    • Scoring
    • Nicks and scratches

Installation Procedure


    Object Number: 1730059  Size: SH
  1. Install a new 3-4 accumulator piston seal (45) to the 3-4 accumulator piston (44).

  2. Object Number: 686979  Size: SH
  3. Install the 3-4 accumulator pin (1) into the transmission case and retain the pin with J 36850 .

  4. Object Number: 647519  Size: SH
  5. Install the 3-4 accumulator piston (2) onto the pin (1) in the transmission case.
  6. Ensure that the 3-4 accumulator piston legs face away from the transmission case.


    Object Number: 686979  Size: SH
  7. Install the J 25025-B  (2, 3) to the transmission case.

  8. Object Number: 2097326  Size: SH
  9. Place the checkball (1) on the spacer plate in the location shown.
  10. Place the 3-4 accumulator spring (2) on the spacer plate.

  11. Object Number: 2035545  Size: SH
  12. Install the J-25025-5 guide pins into the case.
  13. Note: Do not reuse the bonded spacer plate (48). Replace with a NEW bonded spacer plate.

  14. Place the bonded spacer plate on the case.

  15. Object Number: 1283236  Size: SH
  16. Install the spacer plate support plate (53 or 113).
  17. Install the spacer plate bolts (77).
  18. Caution: Refer to Fastener Caution in the Preface section.

  19. Install the accumulator bolt (115), model dependent and tighten the accumulator bolt to 11 N·m (97 lb in).

  20. Object Number: 687023  Size: SH
  21. After installing the spacer plate support (2), look through the hole in the spacer plate to ensure that the checkball (1) has remained in the proper location.
  22. Assemble the 1-2 accumulator. Refer to 1-2 Accumulator Assemble.
  23. Install the 1-2 accumulator. Refer to 1-2 Accumulator Installation.
  24. Remove the J 25025-B from the transmission case.
  25. Install the control valve body. Refer to Control Valve Body Replacement.
  26. Install the transmission oil pan and filter. Refer to Automatic Transmission Fluid and Filter Replacement.
  27. Lower the vehicle.
  28. Fill the transmission to the proper level with DEXRON® VI transmission fluid. Refer to Transmission Fluid Check.
  29. Note: 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.

  30. Reset the TAP values. Refer to Transmission Adaptive Functions.