REVISED END PLAYS FOR 1ST AND 2ND GEAR NOISE REDUCTION 2004R

REVISED END PLAYS FOR 1ST AND 2ND GEAR NOISE REDUCTION

MODELS AFFECTED 1981-1987 VEHICLES EQUIPPED WITH THM 200-4R (MW9) ---------------

BULLETIN COVERS: ---------------- (Figure 1) Some 1981-1987 vehicles equipped with THM 200-4R transmissions may exhibit a gear noise (whine) prior to the 1-2 shift and possibly during 2nd gear. This condition may be caused by a wear pattern on the front planetary gears. This noise may be reduced by replacing worn gearset parts then checking and adjusting the forward clutch shaft end play and the output shaft end play to the specifications in this bulletin.

Note that the specifications given in this bulletin are at the low end of the range printed in the Service Manual and only need to be used to correct a lst/2nd gear noise condition.

SERVICE ACTION: --------------- If worn, replace front internal gear, front carrier assembly and front sun gear. Check and adjust end play to the following specifications:

Forward Clutch Shaft: 0.90mm-1.30mm (0.035"-O.051 ) Output Shaft : 0.32mm-0.64mm (0.013"-O.025")

SERVICE MANUAL REFERENCE: ------------------------- Refer to the THM 200-4R (MW9) Automatic Transmission Unit Repair Manual for overhaul and end play check procedures and selective washer charts.

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.