EARLY TRANS CONVERTER CLUTCH APPLY (INSTALL NEW PROM)

SUBJECT: EARLY TRANSMISSION CONVERTER CLUTCH APPLY (INSTALL NEW PROM)

MODELS: 1992 S/T TRUCK WITH 4.3L AND 4L60 AUTOMATIC TRANSMISSION ----------------------------------------------------------------------------

Some owners of 1992 S/T trucks with 4.3L (LB4) engines and automatic transmissions may comment on early transmission converter clutch (TCC) engagement, TCC engagement just after the 2-3 upshift, or lack of power. This occurs because the torque converter clutch is applied at low speeds during some driving conditions.

SERVICE PROCEDURE:

To correct this condition, install a new calibration PROM that raises the TCC apply speed. This calibration will increase the TCC apply speed on a 1992 vehicle to be similar to a 1991 vehicle (see below).

SERVICE PARTS INFORMATION:

Part PROM Scanner Number Application Broadcast I.D. ------ ----------- --------- ------- 16175285 Federal BARL 5551 16175286 California BARM 5561

Parts are expected to be available on January 27, 1992. In case of limited inventory, parts will be placed on 400 Control to waive VIP surcharges. Only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. However, the part will be shipped premium transportation at dealer's expense and all other order types will be placed on backorder until the 400 control is removed.

WARRANTY INFORMATION:

Labor Operation Number: T0500 Labor Time: 0.8 Hour

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.