TRANS OIL LEAKS 325-4L NEW SPROCKET COVER

Vehicles Affected: All 'E' Series Vehicles Equipped with THM 325-4L Transmission

Beginning August 8, 1983, the THM 325-4L transmission is being produced using a new steel sprocket cover (Figure 1), cork gasket, and special hex head bolts with conical washers (Figure 2). The new sprocket cover has a continuous ribbed flange (Figure 1) to reduce transmission oil leaks.

When servicing any THM 325-4L transmission for a transmission oil leak at the sprocket cover, refer to the following service procedure:

Service Procedure

I. For Transmissions Produced Prior to August 8, 1983

A. Replace the plastic sprocket cover with the new steel sprocket cover. Order service package number 8635964 which contains:

Part No. Quantity Description ------- -------- ------------ 8635855 1 Cover, Sprocket 8639726 1 Gasket, Sprocket Cover 8639743 18 Bolt Asm, With Conical Washer 1 Instruction Sheet

B. Torque all bolts to 8 lbs. ft. (11 N.m).

II. For Transmissions Produced Prior To September, 1982

Where two additional bolt holes (Figure 3) were not included in the case and sprocket cover:

A. Place the new steel sprocket cover onto the case and align the bolt holes.

B. Mark location of the No. 1 hole (Figure 3) onto the case flange.

C. Remove the sprocket cover and drill through the case flange. Use a No. 3 standard (.213 inch) drill bit.

D. Tap the new bolt hole using a 6mm tap.

Notice: Do Not attemp to drill and tap bolt hole No. 2 (Figure 3). The area behind the case flange is a high pressure passage. If drilled too deep, case leaks may result.

E. Install the new steel sprocket cover, gasket and special bolts with conical washers. Order service package 8635964.

F. Torque all attaching bolts to 8 lbs. ft. (11 N.m).

III. All items contained in service package 8635964 are also serviced separately for any transmission produced after August 8, 1983.

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.