For 1990-2009 cars

# SERVO COVER RETAINER RING NEW STYLE WITH TANGS

#### VEHICLES AFFECTED: Some 1985 THM 200-C, 200-4R, and 325-4L Transmissions

During the 1985 model year, a new style servo cover retaining ring (with tangs) is scheduled to go into production on THM 200-C, 200-4R and 325-4L Transmissions (refer to Figure 1). In addition to the new style retaining ring, the notches on the case intermediate servo bore, used for access of retaining ring removal, were omitted (refer to Figure 2).

These changes will provide easier removal and installation of the servo cover retaining ring, as well as prevent damage to the servo cover and piston seals during assembly.

The past style servo cover retaining ring, Part Number 8628137 (without tangs), can be used with the past style (with notches) case intermediate servo bore. The new servo cover retaining ring, Part Number 8657213 (with tangs), can be used with either style case intermediate servo bore.

#### IMPORTANT: Between Julian Date 074 and Julian Date 078 (refer to Figure 3), some new style (notches omitted) THM 200C case intermediate servo bores were assembled with past style servo cover retaining rings (without tangs). If service is required on the new style cases (notches omitted) that have been incorrectly assembled with the past style servo cover retaining ring use the following procedures:

1. Depress intermediate servo cover utilizing Servo Cover Depressor J-29714.

2. Use a small, flat bladed screwdriver to remove servo cover retaining ring.

3. Be certain to reassemble new style intermediate servo bore cases (notches removed) with new style servo retaining ring (with tangs).

Refer to the appropriate service information manual for proper installation procedures.

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.