NO 1-2 SHIFT/SPEEDOMETER INOP OVERHEATED PINION BEARING

MODELS AFFECTED: 1982-1985 ELDORADOS AND SEVILLES

Some Eldorados and Sevilles may experience a final drive noise and/or loss of drive due to an overheated final drive pinion bearing. A preliminary sign of this condition could be a loss of upshifts due to a worn governor gear in the transmission (appearing to be "apple cored," refer to Figure 1). Therefore, the final drive pinion bearings should also be replaced at this time.

Occasionally, the heat that is generated by the bearing may deform the final drive pinion gear shank making it difficult to separate the final drive from the transmission. Excessive force should not be used in attempting to separate the final drive from the transmission, as case damage may result. To separate the two assemblies, proceed as follows:

1. Remove the final drive and transmission as an assembly.

2. Upon removal, disassemble the transmission to the point such that the snap ring that retains the output shaft to the input internal gear can be removed (refer to Figure 2).

3. Once the snap ring is removed, the final drive can be separated from the transmission with the output shaft remaining in the drive pinion.

4. Disassemble and repair the final drive using normal procedures as outlined in Section 4C of the Service Information Manual.

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.