3-4 DOWNSHIFT FLARE SWITCH INFORMATION

VEHICLES AFFECTED: 1984 Corvette Equipped With THM 700-R4 Transmission

Beginning March 5, 1984, (Julian Date 065), 1984 models YA and YW THM 700-R4 transmissions were built with a new Solenoid and "O" Ring Assembly which has a 3 wire harness (Part No. 8654129) which is not connected to the 4-3 Downshift Switch (figure 1). This is done to reduce a possible 4-3 downshift flare. The 4-3 downshift switch will remain a part of the control valve body assembly for the remainder of 1984 production for service reasons.

Models built prior to Julian Date 065 were built with a Solenoid and "O" Ring Assembly that has a 4 wire harness which uses 4-3 Downshift Switch (Figure 2)

The 4 wire harness is superseded by the 3 wire harness (8654129). When servicing the 4 wire harness, replace it with the 3 wire harness and bypass the 4-3 downshift switch as shown in figure 1.

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.