INTERMITTENT NO REVERSE MUST SHIFT TO DRIVE FIRST

MODEL AND YEAR: CELEBRITY MODELS WITH THM440-T4 TRANSAXLE

Celebrity models with THM440-T4 transaxles built before 1987 (Julian date 054) may experience a no reverse engagement condition unless shifted into a forward range prior to shifting into reverse, (i.e., unloading the parking pawl). This condition may be caused by a dent or poor finish on the parking pawl (see Figure 1), which will not allow the pawl to release until unloaded.

To repair this condition, replace the final drive internal gear/parking pawl assembly, P/N 8656372, the actuator guide, plunger and spring assembly, P/N 8656689, and O-Ring seal, bushing actuator or guide, P/N 8646372. The parking pawl and final drive internal gear come as an assembly and cannot be ordered separately. Also, inspect the parking gear, P/N 8644238, for excessive wear or damage and replace as necessary

NOTE: Before installing the replacement parts, inspect the parking pawl to ensure that it has an acceptable surface finish.

Use applicable labor operation and time.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.