A technician should start by raising the vehicle before supporting it and placing a drain pan under the transmission
Oil Pan to remove the Drain Plug and wait for complete fluid drainage in a 4l80-e/4l85-e transmission. Sealant gm p/n 12346004 (Canadian P/N 10953480) should be applied to the Drain Plug threads only if equipped followed by a tightening torque of 18 nm (13 ft. Lbs.). Start by removing the drain pan and supporting the transmission with a transmission jack before moving forward to remove the transmission mount nuts, support bolts and nuts along with side bracket bolts and bracket. Detach the range selector cable from the transmission range selector lever ball stud while maintaining the circular bracket attached to the selector cable. First remove the transmission range selector cable bracket bolts and bracket followed by the Oil Pan bolts. Pay attention to the reusable Oil Pan Gasket since it requires evaluation. Start by removing the Oil Pan along with its gasket, any necessary magnet from the pan bottom and the Oil Filter and filter neck seal before cleaning the transmission case along with the surfaces of the Oil Pan Gasket with solvent. The process begins with placing the filter neck seal and Oil Filter and then proceeding to position the Oil Pan Gasket to the pan and the magnet if needed for installation. Reposition the bracket with cable followed by installation of the transmission range selector cable bracket and bolts at 25 nm (18 ft. Lbs.). Afterward, connect the range selector cable end to the transmission range selector lever ball stud. After securing the transmission range selector cable end to the ball stud of its lever you can reinstall all components starting with the transmission support and side bracket and transmission mount nuts secured at 95 nm (70 ft. Lbs.) followed by tightening the transmission support bolts to 95 nm (70 ft. Lbs.). When done with the transmission jack pullout lower the vehicle before you finalize fluid filling operations using dexron (R)iii transmission fluid to the proper transmission level.