ERRATIC SHIFT 200 & 200C DAMAGED/ROLLED GOV. SEALS

Bulletin Covers: (Refer To Figure 1)

1978 through 1987 vehicle equipped with a THM 200 or THM 200C transmission may have erratic shift patterns (such as late or no pshifts) due to an O-ring seal on the governor cover assembly ausing incorrect governor pressure. NOTE: The erratic shift attern may be more noticeable after the transmission reaches ormal operating temperature.

Service Action: (Refer To Figure 2)

Remove the cover (on car service) and inspect the internal governor cover seal (37). If damaged or rolled, replace the entire governor assembly (36). The seal is not available separately.

Important: Internal governor cover seals must be well lubricated with petrolatum (petroleum jelly) to prevent damage or rolling during installation.

Service Parts Information:

8628933 THM 200C Governor Cover Assembly (with seals 35 and 37)

Service Manual Reference:

Refer to the Automatic Transmission Unit repair section of the 1987 THM 200C Service Manual for proper installation 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.