TORSIONAL VIB WHEN TCC APPLIES SERVICE AND PARTS INFORMATION

(REVISED TO INCLUDE 1982 TO 1987 TRANSMISSIONS)

BULLETIN COVERS:

A new torque converter with a 290 N.m (215 ft. lb.) pressure plate will reduce driveline torsional vibration on 1982 or 1987 T Trucks in third gear around 35 km/h (22 mph - 25 mph.) when the torque converter clutch (TCC) applies and may continue to approximately 80 km/h.

DATE OF PRODUCTION CHANGE: (Figure 1)

Beginning September 12, 1986 (Julian Date 255) 1987 THM 700-R4 transmission models 7TAM, 7TBM were produced with the new torque converter containing the 290 N.m (215 ft. lb.) pressure plate (Figure 2, Item C).

SERVICE ACTION:

The new torque converter can be used to service any 1982 through 1987 THM 700-R4 transmission produced prior to September 12, 1986 (Julian Date 255) for 2.8L T Truck applications only, that have a torsional vibration condition when the TCC applies.

SERVICE PARTS INFORMATION:

8656908 Torque Converter Assembly, Complete

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.