3L80/3L80HD (400/475) Automatic Transmission

1. Disconnect battery ground cable.

2. Remove air cleaner assembly.

3. Disconnect TV/detent cable from its upper end.

4. Remove transmission fluid dipstick

5. Raise and support vehicle.

6. Remove drive shaft from transmission.

7. Disconnect speedometer cable and shift linkage from transmission.

8. Mark then disconnect all electrical connectors from transmission.

9. Remove transmission support braces and flywheel cover assembly.

10. Mark flywheel and torque converter attaching bolts, then remove torque converter to flywheel attaching bolts

11. Disconnect catalytic converter support bracket from transmission assembly.

12. Remove transmission mounting attaching bolts.

13. Place a suitable jack under transmission and raise transmission assembly slightly.

14. Remove transmission support to frame attaching bolts and insulators, if equipped.

15. Slide transmission support rearward and remove from vehicle.

16. Lower transmission slightly, and disconnect transmission fluid cooler lines.

17. Place a suitable jack under engine assembly, then remove transmission to engine attaching bolts.

18. Separate transmission assembly from engine and install torque converter holding tool J-21366 or equivalent

19. Lower transmission from vehicle.

20. Reverse procedure to install.