SOFT 1-2 AND 2-3 SHIFTS NEW PARTS AVAILABLE

MODELS: ALL LIGHT DUTY WITH THM 200-C AUTOMATIC TRANSMISSION

Some THM 200-C transmissions may exhibit a soft 1.2 and 2-3 shift. This condition may be caused by a leak in the intermediate servo piston seal area.

Beginning January, 1984, all THM 200-C transmissions are being produced using a new intermediate servo piston that uses rubber lip seals in place of scarf cut Teflon seal rings..

When servicing any THM 200-C transmissions for a soft 1-2 and 2-3 shift, replace the intermediate servo piston scarf cut seals with the new rubber lip seals. Refer to your parts listing for appropriate intermediate servo piston service package. The new intermediate servo piston lip seals are serviced separately, but must not be installed onto the past intermediate servo piston.

The scarf cut Teflon seal rings will continue to be serviced for past intermediate servo pistons. Refer to Figures No. 1 and 2 to identify the past seals from the new seals and for correct orientation of the new rubber lip seals on the intermediate servo piston.

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.