GM 25939777 Automatic Transmission Control Lever Cable Assembly (At Trns)

You can Select Your Vehicle to check if 25939777 fits your vehicle.

Firmly apply the parking brake and try to momentarily operate the starter in each shift lever position; it should only operate when the shift lever is in PARK or NEUTRAL. If it operates in any other position, adjust the shift cable. If the issue persists after adjustment, the Park/Neutral Position switch may be defective. Disconnect the cable from the negative terminal of the battery, then remove the steering column trim covers, the knee bolster from below the steering column, and the engine cover. Place the transmission in PARK and apply the parking brake, blocking the rear wheels to prevent rolling. At the steering column, disengage the shift cable from the cable bracket using a screwdriver, then disconnect the shift cable end from the lever ballstud. Remove the air filter housing and the shift cable clips from the engine compartment, then raise the vehicle and support it securely on jackstands. Remove the shift cable from the bracket on the transmission and pry the shift cable end from the transmission shift lever. Remove the rubber grommet from the cable at the engine compartment firewall and slide the cable through the opening. Install the cable by reversing the removal procedure, ensuring the grommet seats properly in the firewall, and then adjust the cable. Ensure both the driver's shift lever and the transmission shift lever are in the Park position. For four-speed and six-speed transmissions, remove the shift cable end from the transmission shift lever, double-checking the position of the shift lever in the Park detent. On earlier models, slide the cover towards the end of the shift cable to expose the cable button; on later models, slide the lock tab to release the shift cable adjuster. Push the button on the shift cable out, then push the shift cable end onto the shift lever ballstud until it snaps into place. Press the adjustment button to lock the shift cable and slide the cover back into place, engaging the lock tab on late models to set the correct adjustment. For eight-speed transmissions, raise the vehicle and support it securely on jackstands, ensuring the transmission shift lever is in Park. Align the outside end of the adjuster cable with the inside end of the cable, pushing the inside end of the transmission cable inside the shifter end until the blue spring is fully compressed. Release the transmission end of the cable to allow the spring to adjust it to the proper length, then pull the white cover back and push the off-white lock button down to lock the teeth on the transmission end. Ensure the white cover is over the off-white lock; if not, the shift cable must be readjusted. Finally, lower the vehicle and verify that the transmission can be shifted through all gears.