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Home >> GMC Truck >> 2007 >> Sierra Classic 2500 2WD V8-8.1L >> Repair and Diagnosis >> Transmission and Drivetrain >> Automatic Transmission/Transaxle >> Service and Repair >> Removal and Replacement >> 4L80-E/4L85-E Automatic Transmission >> Transmission Replacement

Transmission Replacement



Transmission Replacement

Tools Required

^ J 21366 Converter Holding Strap

Removal Procedure





1. Raise the vehicle. Refer to Vehicle Lifting.
2. Remove the rear propeller shaft. Refer to One-Piece Propeller Shaft Replacement or Two-Piece Propeller Shaft Replacement.
3. Support the transmission with a suitable jack.
4. Remove the transmission support. Refer to Transmission Support Replacement.
5. Remove the exhaust manifold pipe. Refer to Exhaust Manifold Pipe Replacement.
6. Remove the transmission mount. Refer to Transmission Mount Replacement.
7. Remove the transfer case, if equipped. Refer to Transfer Case Assembly Replacement.





8. Remove the range selector cable from the transmission range selector lever ball stud and bracket. Refer to Automatic Transmission Range Selector Lever Cable Replacement.
9. Disconnect the electrical harness from the park/neutral position switch, the input speed sensor, and the output speed sensor.
10. Disconnect the wire harness from the wire loom on the left side of the transmission.
11. Cut the tie strap to separate the vent hose from the wiring harness.





12. Remove the flywheel inspection cover.
13. Mark the torque converter to flywheel orientation.
14. Remove the torque converter bolts.





15. Remove the transmission heat shield.





16. Disconnect the transmission oil cooler lines from the transmission. Refer to Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection.
17. Plug the transmission oil cooler line connectors in the transmission case.





18. Remove the stud and the bolt on the right side securing the transmission to the engine.





19. Remove the remaining 6 studs and the one bolt securing the transmission to the engine.
20. Install the J 21366 onto the transmission bell housing to retain the torque converter.
21. Pull the transmission straight back.
22. Remove the transmission from the vehicle.
23. Flush the transmission oil cooler and lines at this time. Refer to Transmission Fluid Cooler Flushing and Flow Test (J 35944-A) Transmission Fluid Cooler Flushing and Flow Test (J 45096).

Installation Procedure





1. Install the J 21366 onto the transmission bell housing to retain the torque converter.
2. Raise the transmission into place and remove the J 21366 from the transmission.
3. Slide the transmission straight onto the locating pins while lining up the marks on the flywheel and the torque converter. The torque converter must rotate freely by hand.

4. Notice:
Refer to Fastener Notice.

Install studs and bolt securing the transmission to the engine.

Tighten the studs and the bolt to 50 Nm (37 ft. lbs.).





5. Install the stud and bolt on the right side securing the transmission to the engine.

Tighten the stud and the bolt to 50 Nm (37 ft. lbs.).





6. If reusing the torque converter bolts with a 6.0L engine, clean the bolt threads and apply LOCTITE 242 GM P/N 12345382 (Canadian P/N 10953489), or equivalent to the threads prior to installation.
7. If reusing the torque converter bolts with a 8.1L engine, clean the bolt threads and apply LOCTITE 272 GM P/N 12345493 (Canadian P/N 10953488), or equivalent to the threads prior to installation.
8. Line up the marks made during removal and install the flywheel to torque converter bolts.

Tighten the bolts to 60 Nm (44 ft. lbs.).

9. Install the torque converter cover to the transmission.
10. Install the bolts securing the torque converter cover.

Tighten the bolts to 33 Nm (24 ft. lbs.).





11. Install the vent hose to the wiring harness using a new tie strap.
12. Connect the wiring harness to the wiring loom on the left side of the transmission.
13. Connect the electrical harness to the park/neutral position switch, the input speed sensor, and the output speed sensor.
14. Install the range selector cable to the transmission range selector lever ball stud and bracket. Refer to Automatic Transmission Range Selector Lever Cable Replacement.





15. Install the transfer case, if equipped. Refer to Transfer Case Assembly Replacement.
16. Install the transmission mount. Refer to Transmission Mount Replacement.
17. Install the exhaust manifold pipe. Refer to Exhaust Manifold Pipe Replacement.
18. Install the transmission support. Refer to Transmission Support Replacement.
19. Remove the transmission jack.
20. Install the rear propeller shaft. Refer to One-Piece Propeller Shaft Replacement or Two-Piece Propeller Shaft Replacement.





21. Connect the transmission oil cooler lines to the transmission. Refer to Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection.





22. Install the transmission heat shield.
23. Install the bolts securing the heat shield to the transmission.

Tighten the bolts to 17 Nm (13 ft. lbs.).

24. Lower the vehicle.
25. Fill the transmission to the proper level. Refer to Transmission Fluid Check.

26. 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.

Reset the TAP values. Refer to Transmission Adaptive Functions.
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