GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1998 🢒 Chevy K Pickup - 4WD 🢒 Transmission/Transaxle 🢒 Automatic Transmission - 4L80-E 🢒 Center Support and Gear Unit Assembly Disassemble

    Object Number: 54555 Size: SH
  1. Separate the center support assembly (640) from the reaction drum and carrier assembly (651).
  2. Remove the support/reaction drum thrust washer (642) (brass). The thrust washer may be stuck to the center support assembly.

    3. Object Number: 54557 Size: SH
  3. Remove the sun gear shaft (649).
  4. Inspect the sun gear shaft (649) for the following:
    5. • Nicked, scored or worn bushings
    • Damaged splines and teeth
    • Cracks

    Object Number: 54558 Size: SH
  5. Remove the reaction drum and carrier assembly (651) from the output carrier assembly (661).
  6. Remove the roller clutch assembly (644) from the reaction drum and carrier assembly (651).
  7. Inspect the reaction drum and carrier (651) assembly for the following:
    8. • The pinion gear and pocket thrust surfaces for damage
    • Cracks or damage to band apply surface
    • Pinion gear damage
    • Planetary pinion gear pin for proper location (walking)
    • The bushings for damage
  8. Inspect the roller clutch assembly (644) for damage to the rollers, springs and cage surfaces.

    9. Object Number: 54559 Size: SH
  9. Remove the sun gear front thrust bearing assembly (647).
  10. Remove the sun gear thrust bearing races (646, 648). One race (646) may be stuck to the center support assembly.
  11. Remove the sun gear (650).
  12. Remove the front internal/reaction carrier washer (659) from the output carrier assembly (661).
  13. Inspect the thrust washers, the bearings and the races for damage.
  14. Inspect the sun gear teeth for damage.

    15. Object Number: 28434 Size: SH
  15. Turn the output carrier assembly (661) over so that the output shaft (671) faces up.
  16. Remove the output shaft thrust washer (673).
  17. Remove the output shaft retainer ring (672).
  18. Remove the output shaft (671).
  19. Inspect the output shaft (671) for the following:
    20. • Stripped splines
    • Damaged teeth
    • Cracks
    • Damage to the bushing
  20. Remove the thrust bearing (647) and the thrust bearing races (648, 669) from the rear internal gear (666). The thrust bearing may be stuck to the output shaft (671).
  21. Inspect the thrust bearing and races for damage.

    22. Object Number: 54562 Size: SH
  22. Remove the rear internal gear (666) and the main shaft (662) from the output carrier assembly (661).
  23. Remove the rear internal gear thrust bearing (664) and races (663 and 665).
  24. Inspect the thrust washers, the bearings, and the races for damage.

    25. Object Number: 54564 Size: SH
  25. Remove the main shaft retainer ring (670). Hold the main shaft (662) so it will not fall and become damaged.
  26. Remove the main shaft (662) from the rear internal gear (666).
  27. Inspect the main shaft (662) for damaged splines.
  28. Inspect the main shaft (662) for wear.
  29. Inspect the rear internal gear (666) for the following:
    30. • Stripped splines
    • Damaged teeth
    • Wear

    Object Number: 28437 Size: SH
  30. Clean all components thoroughly.
  31. Inspect the output carrier assembly (661) for the following:
    32. • Excessive wear
    • Damage to the park pawl lugs
    • Damage to the pinion gears
    • Excessive wear to the pinion gear steel and brass washers
    • Damage to the pinion gear and pocket thrust surfaces.
  32. Inspect the front internal gear for damage and cracks.
  33. Inspect the output speed sensor ring (660) for tightness and damage.