Some HYDRA-MATIC 3L80 models built from August lst (Julian Date 213) through October 1989 (Julian Date 304) may lose all torward ranges. This may be caused by an unfinished turbine shaft journal which distresses the stator shaft rear bushing and causes loss of forward clutch. Changing the Turbine shaft, Forward Clutch Housing Assembly and Pump Cover Assembly will eliminate any future concerns. If further inspection shows any contamination, the Converter Assembly should also be replaced and the transmission cooler and lines flushed.
Part Number Part Name
8624908 Package, Forward Clutch Housing & Washer ----------------------------- 8625955 Package, Cover Assembly Pump -----------------------------
Parts are currently available through GMSPO.
Refer to the Unit Repair Section of the appropriate Service Manual for the proper replacement procedures.
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.