GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2004 🢒 Century 🢒 Transmission/Transaxle 🢒 Automatic Transmission - 4 Speed-M41 🢒 Center Support Assembly Reconditioning Repair

Tools Required

    • J 8059 Parallel Jaws
    • J 41681 Clutch Spring Compressor
    • J 8001 Dial Indicator Set
    • J 26900-13 Magnetic Base

Removal and Measurements

    Object Number: 153793 Size: SH
  1. Remove the planetary gear snap ring using the J 8059 .

    2. Object Number: 153794 Size: SH
  2. Remove the planetary gear (1) from the center support (2).

    3. Object Number: 153796 Size: SH
  3. Measure the B1 brake piston stroke using J 8001 and J 26900-13 :
    4. • Place the J 8001 plunger on the B1 brake piston.
    • Apply 392-785 kPa (57-114 psi) of air pressure into the extreme left overdrive case fluid passage.
    • Measure the B1 brake piston stroke.

    Specification
    B1 brake piston stroke (standard): 0.63-1.73 mm (0.025-0.068 in)

    • If the B1 brake piston stroke is not within specifications, replace the brake flange or the disc.

    Object Number: 153813 Size: SH
  4. Remove the 3 rear sealing rings (1) from the center support.

    5. Object Number: 153808 Size: SH
  5. Remove the B1 brake clutch snap ring (2) from the center support (1) using a flathead screwdriver.

    6. Object Number: 153809 Size: SH
  6. Remove the following B1 brake components from the center support:
    7. • The flange (1)
    • The clutch discs (2)
    • The clutch plates (3)

    Object Number: 153810 Size: SH
  7. Remove the B1 brake piston return spring snap ring from the B1 brake piston retainer (1) using J 41681 and a hydraulic press.

    8. Object Number: 153811 Size: SH
  8. Remove the B1 brake piston return springs from the center support (1).

    9. Object Number: 153812 Size: SH

    Important: When using compressed air to remove components, air pressure should not exceed 98 kPa (14 psi).

  9. Apply low pressure compressed air to the extreme left fluid passage (1) in order to remove the B1 brake piston.
  10. Remove the O-rings from the B1 brake piston.

    11. Object Number: 153814 Size: SH
  11. Measure the B2 brake piston stroke using J 8001 and J 26900-13 :
    12. • Place the J 8001 plunger on the B2 brake piston.
    • Apply 392-785 kPa (57-114 psi) of air pressure into the second left overdrive case fluid passage (1).
    • Measure the B2 brake piston stroke.

    Specification
    B2 brake piston stroke (standard): 1.01-2.25 mm (0.040-0.088 in)

    • If the B2 brake piston stroke is not within specifications, replace the brake flange or the disc.
  12. Remove the B2 brake snap ring from the center support.
  13. Remove the following B2 brake components from the center support:
    14. • The flange
    • The clutch discs
    • The clutch plates

    Object Number: 153815 Size: SH
  14. Remove the B2 brake piston return spring snap ring from the B2 brake piston retainer using the J 41681 and a hydraulic press.
  15. Remove the B2 brake piston return springs from the center support (1).

    16. Object Number: 153816 Size: SH

    Important: When using compressed air to remove components, air pressure should not exceed 98 kPa (14 psi).

  16. Apply low pressure compressed air to the second left fluid passage (1) in order to remove the B2 brake piston (2).
  17. Remove the O-rings from the B2 brake piston.

    18. Object Number: 883681 Size: SH
  18. Perform the following steps in order to inspect the planetary sun gear (4) operation:
    19. 18.1. Hold the B2 brake hub assembly (3).
    18.2. Inspect that the gear locks when turned in the clockwise direction (1).
    18.3. Inspect that the gear turns freely in the counter clockwise direction (2).

    Object Number: 153819 Size: SH
  19. Remove the B2 brake hub assembly (1) from the planetary sun gear (2).

    20. Object Number: 153820 Size: SH
  20. Remove the two planetary sun gear sealing rings (2).

Installation Procedure
  1. Install the two planetary sun gear seal rings.
  2. Lubricate the seal rings with A/T fluid.
  3. Install the B2 brake hub assembly to the planetary sun gear.
  4. Install 2 new O-rings (1) to the B2 brake piston.
  5. Lubricate the O-rings with A/T fluid.
  6. Install the B2 brake piston to the center support.
  7. Install the B2 brake piston return springs to the B2 brake piston.

    8. Important: Do not align the snap ring opening with B2 brake piston return spring retainer lug (2) during the next step.


    Object Number: 153821 Size: SH
  8. Install the B2 brake piston return spring snap ring onto the B2 piston return spring retainer using J 41681 and a hydraulic press.
  9. Install the B2 brake plates and discs in the following order:
    10. 9.1. The plate
    9.2. The disc
    9.3. The plate
    9.4. The disc
    9.5. The plate
    9.6. The disc

    Object Number: 153822 Size: SH
  10. Install the B2 brake flange (1) with the chamfered side facing the disc (2).
  11. Install the B2 snap ring into the center support.

    12. Object Number: 153814 Size: SH
  12. Measure the B2 brake piston stroke using J 8001 and J 26900-13 :
    13. • Place J 8001 plunger on the B2 brake piston.
    • Apply 392-785 kPa (57-114 psi) of air pressure into the second left overdrive case fluid passage (1) .
    • Take the measurement.

    Specification
    B2 brake piston stroke (standard): 1.01-2.25 mm (0.040-0.088 in)

    • If the B2 brake piston stroke is not within specifications, disassemble and inspect.
  13. Install 2 new O-rings to the B1 brake piston.
  14. Lubricate the O-rings with A/T fluid.
  15. Install the B1 brake piston to the center support.
  16. Install the B1 brake piston return springs to the B1 brake piston.
  17. Install the B1 brake piston return spring snap ring onto the B1 brake piston return spring retainer using J 41681 and a hydraulic press.
  18. Install the B1 brake plates and discs in the following order:
    19. 18.1. The plate
    18.2. The disc
    18.3. The plate
    18.4. The plate
    18.5. The disc
  19. Install the B1 brake flange with the chamfered side facing the disc.
  20. Install the B1 snap ring into the center support.

    21. Object Number: 153796 Size: SH
  21. Measure the B1 brake piston (1) stroke using J 8001 and J 26900-13 :
    22. • Place the J 8001 plunger on the B1 brake piston.
    • Apply 392-785 kPa (57-114 psi) of air pressure into the extreme left overdrive case fluid passage.
    • Take the measurement.

    Specification
    B1 brake piston stroke (standard): 0.63-1.73 mm (0.025-0.068 in)

    • If the B1 brake piston stroke is not within specifications, disassemble and inspect.
  22. Install the three rear seal rings to the center support.
  23. Lubricate the seal rings with A/T fluid.
  24. Install the planetary gear to the center support.
  25. Install the planetary gear snap ring using J 8059 .