LOSS OF POWER IN DRIVE DIESEL INFORMATION

MODELS: 1982-1984 LIGHT DUTY WITH AUTOMATIC TRANSMISSION AND DIESEL ENGINES

Beginning with 1984 models, new torque converters went into production which have the blades retained into the converter pump shell by a braze process. Blades which have moved in a converter may reduce torque multiplication causing a loss of power effect under 35 mph.

When servicing any 1981 through 1984 THM 400, or 700-R4 transmissions, and torque converter replacement is required, refer to the chart below for replacement part numbers, converter identification, and model application.

THM Model Part No. New Ident. Application By Model

THM 400 8629917 4M 1982 FD, FF, FX, FY. 1983 FD, FF, FR, FS, FU, FX, FY. 1984 FD, FF, FR, FS, FU, FV, FX, MA. THM 700-R4 8642992 CGAD 1982 9TN, 9TP, 9M6, 9MH. 1983 3MH, 3TL, 3TP, 3TS, 3TZ, 3T8 3VJ. 1984 4MG, 4MH, 4TL, 4TM, 4TZ, 4T8, 4VE, 4VJ, 4VX.

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.