* Shift linkage problems: The linkage connecting the gear selector to the transmission might be worn, bent, broken, or improperly adjusted. This is a common culprit, allowing the transmission to shift unintentionally.
* Transmission problems: Issues within the transmission itself, such as worn internal components or a failing shift mechanism, could cause it to slip out of park. Low transmission fluid or fluid leaks also contribute.
* Park pawl failure: The park pawl is a mechanical device that locks the transmission in the park position. If it's worn, broken, or not engaging properly, the vehicle can roll.
* Steering column issues: Problems with the steering column's shift linkage or internal components could affect the transmission's ability to stay in park.
* Electrical problems: While less common for simply coming out of park, a short circuit or faulty wiring in the shift interlock system (the system that prevents shifting unless the brake is pressed) could allow the transmission to shift unexpectedly. This is more likely to lead to the truck starting in gear without the key in the ignition.
* Improper repair: A previous repair to the transmission, shift linkage, or steering column might not have been done correctly, leading to this problem.
Important Note: A vehicle rolling unexpectedly is incredibly dangerous. If your 1995 Chevrolet 1500 is exhibiting this behavior, do not drive it. Have it towed to a qualified mechanic for diagnosis and repair immediately. Driving a vehicle with this problem could result in a serious accident.
