DRIVE LINK NOISE-IN PARK/ NEUTRAL

SUBJECT: TRANSAXLE NOISE IN PARK/NEUTRAL

MODELS AFFECTED: 1985-1991 DE VILLES AND FLEETWOODS 1986-1991 ELDORADOS AND SEVILLES 1987-1991 ALLANTES

Some 1985-1991 DeVilles and Fleetwoods, 1986-1991 Eldorados and Sevilles, and 1987-1991 Allantes may exhibit a whine/whistle (similar to generator whine) or a growling noise in park and neutral which varies with engine speed. However, this noise will stop when the transaxle is shifted into drive or reverse range with the vehicle not moving (brakes applied).

Drive link noise may be caused by worn or damaged sprocket/drive link components or by a damaged drive sprocket support bearing.

IMPORTANT: Other transmission noises may sound similar but occur during different vehicle conditions.

o Final drive noise (hum) varies with vehicle speed and may be most noticeable under light throttle acceleration.

o Planetary gear noise (whine) is most noticeable when driving in first gear or reverse range. Gear noise diminishes or becomes less noticeable after an upshift.

o Pump noise (high pitch whine) varies with engine speed and may be affected by modulated line pressure boost. Pump noise is noticeable in all operating ranges.

Service Procedure:

F-7 Allante - Replace transaxle with a SRTA.

4T60 or 4T60-E - Inspect for worn or damaged drive link components. Refer to Service Bulletin T-90-75, Group 7. Worn or damaged components should be serviced per the unit repair section of the appropriate Service Information Manual. If the above inspection does not reveal any visual damage, replace the drive sprocket support bearing. Refer to figure 1, Item 516.

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.