BINDING/NO REVERSE CONTROL VALVE ASSEMBLY

VEHICLES AFFECTED: Some 1985 THM 325-4L OE and OQ Models

Some 1985 THM 325-4L OE and OQ models built prior to Julian date 074 (REFER TO FIGURE 1) may experience a binding or dragging condition in reverse range, or no reverse operation. This condition may be caused by application of the forward clutch while in reverse range which may be due to a hydraulic feed into the 1-2 accumulator circuit of the control valve assembly.

If the condition(s) occurs, IT IS NECESSARY to replace the control valve assembly. Do not attempt to service the 1-2 accumulator bushing/valve to repair the conditions(s).

Replace 1985 THM 325-4L model OE with control valve assembly part number 8639675 and 1985 THM 325-4L model OQ with control valve assembly part number 8639804.

Refer to the appropriate service information 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.