3-4 ACCUMULATOR PISTON/O-RING IS WITHIN NOT VISABLE ON EXTER

Subject: NEW DESIGN 3 - 4 ACCUMULATOR PISTON AND "O" RING SEAL 1982 THM 200-4R

Beginning approximately mid-October, 1981, all 1982 THM 200-4R transmissions were built with a new design 3-4 accumulator piston and "O" ring seal, to enhance the 3-4 accumulator piston sealing capacity. See Figure 1.

The past design 3-4 accumulator "O" ring was composed of a semi-flexible P.T.F.E. compound. The new design 3-4 accumulator "O" ring is a synthetic rubber seal.

SERVICE INFORMATION

1. The new design 3-4 accumulator piston and seal are available as a service package (P/N 8634956).

2. The new design 3-4 accumulator "O" ring seal is also available separately (P/N 8635568).

3. To replace a past design 3-4 accumulator piston or seal use service package (P/N 8634956).

4. The new design and past design parts are not interchangeable.

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.