GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2000 🢒 GMC K Pickup - 4WD 🢒 Transmission/Transaxle 🢒 Automatic Transmission - 4L80-E 🢒 Forward Servo Replacement

Removal Procedure
  1. Lift the vehicle. Refer to Lifting and Jacking the Vehicle .
  2. Remove the oil pan and filter. Refer to Automatic Transmission Fluid and Filter Replacement .
  3. Remove the six forward servo cover bolts, cover, and gasket.

    4. Object Number: 512978 Size: SH
  4. Remove the following parts:
    5. 4.1. Forward servo piston pin (5)
    4.2. O-ring seal (4)
    4.3. Servo piston (3)
    4.4. Retainer (2)
    4.5. Piston spring (1)

Installation Procedure

    Object Number: 512978 Size: SH
  1. Install the following parts:
    2. • Piston spring (1)
    • Retainer (2)
    • Servo piston (3)
    • O-ring seal (4)
    • Forward servo piston pin (5)

    Notice: Refer to Fastener Notice in the Preface section.

  2. Install the six forward servo gasket, cover, and six bolts.

    3. Tighten
    Tighten the bolts to 24 N·m (18 lb ft).

  3. Install the oil pan and filter. Refer to Automatic Transmission Fluid and Filter Replacement .
  4. Lower the vehicle.

    5. 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 ECM, PCM or TCM will need to relearn TAP values. Transmission performance may be affected as new TAP values are learned.

  5. Reset the TAP values. Refer to Adapt Function .