GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2007 🢒 Yukon Denali 🢒 Transmission/Transaxle 🢒 Automatic Transmission - 4L80-E/4L85-E 🢒 Reverse Servo Replacement

Removal Procedure

    Object Number: 512992 Size: SH
  1. Remove the transmission filter. Refer to Automatic Transmission Fluid and Filter Replacement .
  2. Remove the rear servo from the transmission case in the following order:
    3. 2.1. Cover bolts (6)
    2.2. Cover (5)
    2.3. Cover gasket (4)
    2.4. Bottom retaining clip (3)
    2.5. Servo piston (2)
    2.6. Outer ring oil seal (1)
    2.7. Inner ring oil seal (7)
    2.8. Accumulator piston (8)
    2.9. Piston seal (9)
    2.10. Washer (10)
    2.11. Servo spring (11)
    2.12. Servo spring retainer (12)
    2.13. Selective pin (13)
    2.14. Accumulator spring (14)

Installation Procedure

    Object Number: 512992 Size: SH
  1. Install the rear servo to the transmission in the following order:
    2. 1.1. Accumulator spring (14)
    1.2. Selective pin (13)
    1.3. Servo spring retainer (12)
    1.4. Servo spring (11)
    1.5. Washer (10)
    1.6. Piston seal (9)
    1.7. Accumulator piston (8)
    1.8. Inner ring oil seal (7)
    1.9. Outer ring oil seal (1)
    1.10. Servo piston (2)
    1.11. Bottom retaining clip (3)
    1.12. Cover gasket (4)
    1.13. Cover (5)

    Notice: Refer to Fastener Notice in the Preface section.

    1.14. Cover bolts (6)
  2. Tighten the cover bolts.

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

  3. Install the transmission filter. Refer to Automatic Transmission Fluid and Filter Replacement .

    4. 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.

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