1985 Service Manuals using the THM 700-R4 Automatic Transmission section should be updated with the information contained in this bulletin.
The Lo & Reverse Clutch Piston dimensions shown in Figure 70 on Page 700-R4-47 should be 60.92 mm (2.398 in.) for the following 1985 Models: PR,MT, VC, PQ, ML, MP, MS, T7. The dimension for ALL OTHER 1985 models should be 56.52 mm (2.225 in.).
Refer to Figure 1 to update your 1985 Service Manual.
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.