GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2001 🢒 Yukon XL - 2WD 🢒 Transmission/Transaxle 🢒 Automatic Transmission - 4L80-E 🢒 Center Support and Gear Unit Assembly Assemble

Tools Required

    • J 6116-A Rear Gear Holding Fixture
    • J 36850 Transjel® Lubricant

    Object Number: 54575 Size: SH
  1. Insert the main shaft (662) into the rear internal gear (666).
  2. Install the main shaft retainer ring (670) onto the main shaft (662).

    3. Object Number: 334798 Size: SH
  3. Install the washer (691) onto the main shaft (662).
  4. Install the sun gear rear thrust bearing assembly (664) and bearing races (663, 665) onto the main shaft (662).
  5. The lips on the sun gear thrust bearing races (663, 665) should face the sun gear rear thrust bearing assembly (664).
  6. Retain the washer, sun gear rear thrust bearing assembly and bearing races with J 36850 or equivalent.

    7. Object Number: 28722 Size: SH
  7. Lubricate the output carrier pinion gears (655) with DEXRON®VI transmission fluid.
  8. Install the main shaft (662) and the rear internal gear (666) into the output carrier assembly (661).
  9. Place the assembly into the J 6116-A with the main shaft facing down.

    10. Object Number: 54649 Size: SH
  10. Assemble the rear internal gear thrust bearing assembly (647) and races (648, 669). The lips of the sun gear thrust bearing races  (648, 669) should face the rear internal gear thrust bearing assembly (647).
  11. Place the bearing and race assembly onto the hub of the rear internal gear (666). Retain with J 36850 or equivalent.

    12. Object Number: 28725 Size: SH
  12. Install the output shaft assembly (671) into the output carrier assembly (661).
  13. Install the output shaft retainer ring (672).
  14. Install the output shaft thrust washer (673) on the output shaft assembly (671). Align the output shaft thrust washer tabs with the pockets in the output carrier assembly.
  15. Retain the thrust washer with J 36850 or equivalent.

    16. Object Number: 54584 Size: SH
  16. Turn the gear unit assembly over and place it into the J 6116-A with the output shaft assembly (671) facing down.
  17. Install the output carrier thrust washer (659) into the output carrier assembly (661).
  18. Lubricate the reaction carrier pinion gears (655) with DEXRON®VI transmission fluid.
  19. Install the reaction carrier assembly (651) into the output carrier assembly (661).
  20. Rotate the reaction carrier assembly (651) to ease installation.

    21. Object Number: 54593 Size: SH
  21. Install the sun gear (650) into the reaction carrier assembly (651).
    22. • Insert the chamfered inner diameter first.
    • Rotate the sun gear to ease installation.
  22. Insert the sun gear shaft assembly (649) with the long splined end into the sun gear (650).

    23. Object Number: 54600 Size: SH
  23. Install the longer-lipped sun gear front thrust bearing race (648) onto the sun gear with the lip facing upward.
  24. Assemble the sun gear front thrust bearing assembly (647) onto the sun gear front thrust bearing race (648).

    25. Object Number: 54607 Size: SH
  25. Install the sun gear front thrust bearing race (646) on the rear hub of the center support assembly (640). Retain the sun gear front thrust bearing race (646) with J 36850 or equivalent.
  26. Install the reaction carrier thrust washer  (642) (brass) into the recess of the center support assembly (640). Retain the reaction carrier thrust washer (642) with J 36850 or equivalent.

    27. Object Number: 28733 Size: SH
  27. Install a new center support assembly (640), or the reconditioned center support assembly, into the reaction carrier assembly (651).
  28. Verify correct installation by holding the reaction carrier assembly (651) stationary and rotating the center support assembly (640). The center support assembly (640) should only turn counterclockwise.