TIE - UP IN REVERSE 700-R4 STICKING VALVE

VEHICLES AFFECTED: 1983-84 Passenger Cars and Trucks Equipped With THM 700-R4 Transmissions

Some 1983 and 1984 THM 700-R4 transmissions may experience a partial tie-up in reverse. This may be caused by a sticking 4-3 sequence valve which could cause a partial band apply or a sticking 2-3 shift valve which could cause a partial 3-4 clutch apply. When servicing for this condition refer to the following procedure:

1. Remove the control valve body assembly from the transmission.

2. Disassemble the control valve body assembly and wash all parts with solvent.

3. Visually inspect the 4-3 bequence valve and valve train and the 2-3 shift valve and valve train for nicks, burrs, chips, and damage (Figure 1).

4. If valves or bushings are damaged, replace the control valve body assembly.

5. If valves and bushings are OK, reassemble the control valve body assembly and install back onto the transmission.

Refer to the Service Manual for disassembly and reassembly of the control valve body assembly.

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.