SLIPS IN REVERSE OR NO REVERSE PISTON SNAP RING LOCATION

MODELS AFFECTED: 1989-90 3T40 TYPE TRANSMISSIONS (THM 125C)

BULLETIN COVERS

Incorrectly installed Lo-Reverse Piston Snap Rings (657) that may cause a slip in reverse and/or no reverse condition.

SERVICE PROCEDURE (Refer to Figure 1)

Whenever installing the Lo-Reverse Clutch Piston Snap Ring (657), the step on the outside diameter of the snap ring must be positioned toward the Lo-Reverse Clutch retainer (656). The retainer must rest inside the snap ring to allow proper piston travel.

If the snap ring is installed backwards with the step facing the splines on the hub, the retainer may limit travel of the piston and may result in a durability concern.

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.