GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2006 🢒 TopKick C-Series (Conventional) C4/C5 🢒 Transmission/Transaxle 🢒 Automatic Transmission - 4 Speed-MU4 🢒 Forward Clutch Removal

Tools Required
    • J 7872 Magnetic Base Indicator Set
    • J 23327 Clutch Spring Compressor

    Object Number: 164981 Size: SH
  1. Use a J 7872 in order to measure the forward clutch piston stroke before disassembly.
    2. 1.1. Temporarily install the direct clutch assembly onto the fluid pump  (2) and the forward clutch assembly into the direct clutch assembly.
    1.2. Place the J 7872 plunger on the forward clutch piston and apply 392-785 kPa (57-114 psi) of compressed air into the forward clutch apply passage on the fluid pump.
    1.3. Standard forward clutch piston stroke should fall within 1.420-1.810 mm (0.0559-0.0713 in).

    Object Number: 164982 Size: SH
  2. If a correct reading cannot be obtained, remove the forward clutch assembly from the direct clutch assembly. Apply 392-785 kPa (57-114 psi) of compressed air into the forward clutch assembly passage  (1) on the input shaft  (2) and observe the J 7872 .
  3. If the forward clutch piston stroke is greater or less than specified, inspect all direct clutch components for excessive wear.

    4. Object Number: 164997 Size: SH
  4. Remove the three input shaft seal rings  (2) from the input shaft  (1).

    5. Object Number: 165018 Size: SH
  5. Remove the forward clutch snap ring  (2) from the forward clutch drum  (1).

    6. Object Number: 165019 Size: SH
  6. Remove the following components from the forward clutch drum (1):
    7. • The forward clutch flange
    • Four discs
    • Four plates

    Object Number: 165021 Size: SH
  7. Use the J 23327 and a hydraulic press to remove the forward clutch piston return spring snap ring (1) from the forward clutch piston return spring retainer.
  8. Remove the forward clutch piston return spring from the forward clutch piston.

    9. Object Number: 165024 Size: SH
  9. Remove the forward clutch piston  (1) from the forward clutch drum  (2) by applying low pressure compressed air into the forward clutch apply passage on the input shaft.
  10. Remove the two forward clutch piston seals from the forward clutch piston.
  11. Clean all the forward clutch components and dry thoroughly.
  12. Inspect the forward clutch discs for excessive wear or damage. Replace the discs as necessary.
  13. Inspect the forward piston for cracks or porosity. Replace the piston as necessary.

    14. Object Number: 165026 Size: SH
  14. Inspect the forward clutch piston check ball  (1) operations by applying compressed air into the working and release sides of the forward clutch piston  (2). There must be no air leakage on the working side and air must pass freely through the release side. If these conditions do not exist, replace the forward clutch piston.
  15. Inspect the forward clutch piston return spring for distortion or weakness. Replace the spring as necessary.