Start by applying the park brake followed by shifting the transmission into neutral before replacing the park/neutral position switch on the 4l60-e/4l65-e transmission. Vehicles equipped with 4-wheel drive require the removal of the front propeller shaft before proceeding. Begin by safely elevating the vehicle before disconnecting the electrical connector for the park/neutral position (PNP) switch. Start by removing the manual shaft lever nut followed by the transmission control lever from the manual shaft. Next, remove the pnp switch bolts and take the pnp switch off the manual shaft; file the manual shaft's outer edge with a file to smooth any surface burrs when the manual shaft resists sliding off easily. Installation begins with aligning the pnp switch to the manual shaft flats before sliding it onto the shaft until the switch mounting bracket engages with the transmission mounting bosses. A brand-new pnp switch installs with a positive assurance bracket so the park neutral switch aligner becomes unnecessary. Centrally torque the pnp switch bolts first, then utilize the park neutral switch aligner (J 41364-A) to align switch slots with tool lower tabs. Follow by rotating the tool to allow its upper locating pin to face towards the switch top. Tighten the bolts to 25 nm (18 ft. Lbs.). First remove the park neutral switch aligner (J 41364-A) and eliminate the positive assurance bracket (if present) from the system. Reinstall the transmission control lever onto the manual shaft with the nut, tightening it to 25 nm (18 ft. Lbs.)reconnect the pnp switch electrical connector after reattaching the pnp switch. If the vehicle has 4wd, reinstall the front propeller shaft, lower the vehicle, and check the switch for proper operation, ensuring the engine starts only in the park (P) or neutral (N) positions; replace the switch when it fails to operate correctly.