HIGH PITCHED WHINE THM325-4L PUMP DRIVE GEAR RUBBING

MODELS AFFECTED: 1984 ELDORADO AND SEVILLE

1984 Cadillacs equipped with a THM 325-4L transmission and HT4100 engine may experience a high pitched whining noise noticeable in all shifter positions, including Park and Neutral. This condition can be caused by interference between the transmission pump drive gear and body crescent.

When servicing vehicles experiencing this condition, refer to the following service procedure.

Service Procedure

1. Identify the transmission model and serial number. The I.D. tag is located on the left side of the case bell housing. Noisy pumps should be confined to the following 1984 model and serial numbers:

MODEL SERIAL NUMBER ----- ------------- AE 2172 to 2296 AJ 31694 to 34426

2. If the transmission is in the range listed above, replace the pump and gear assembly (PIN 8635022) and flush the cooler tank and lines following procedures outlined in Sections 7A and 325-4L of the Service Information Manual.

For warranty purposes, use labor Operation No. T6090 at 5.1 hours.

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.