TRANSAXLE BRG. WHINE AUDIBLE IN 1ST,2ND, & 3RD GEAR

SUBJECT: TRANSAXLE BEARING WHINE AUDIBLE IN 1ST, 2ND, AND 3RD GEAR - REPLACE BEARING ASSEMBLY

MODEL/YEARS: VEHICLES EQUIPPED WITH HYDRA-MATIC 4T60-E TRANSAXLES (RPO-M13)

CONDITION: Some vehicles equipped with a HYDRA-MATIC 4T60-E (RPO M13) transaxle built on or before June 23, 1993 (Julian Date 174), may exhibit a transaxle bearing whine that is audible in 1st, 2nd, and 3rd gear. The whine is most audible on the "driver's" side of the vehicle while in 2nd gear during a light throttle acceleration.

Note: This bearing whine cannot be heard in "Park" or "Neutral."

CAUSE: (See illustration below)

The "Bearing Assembly, 4th Channel Plate Hub/Channel Plate" (503/431) may have been improperly installed causing the needle bearings to leave indentation marks on the bearing race.

CORRECTION: Replace the "Bearing Assembly, 4th Channel Plate Hub/Channel Plate" (503/431) located on the "Channel Plate Assembly" (404/401).

PART INFORMATION: P/N for the "Bearing Assembly, 4th Channel Plate Hub/Channel Plate" is the same for the 4T60 and 4T60-E transaxle. Parts are currently available from GMSPO.

Part Number Description ----------- ----------- 8656393 Bearing Assembly, 4th Channel Plate Hub/Channel Plate

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.