Drive Axle - Wobble Vibration Between 20-35 MPH
Bulletin: 92-4-1Date: Oct. '92
Ref.No.: 92-298-4
Corp.Ref.No.: 214401
SUBJECT:
DRIVE AXLE "WOBBLE" VIBRATION BETWEEN 20-35 MPH (INSTALL S-PLAN SPIDERS AND BEARING BLOCKS)
MODELS AFFECTED:
1988-92 RIVIERA
Some 1988-92 Riviera's built prior to VIN breakpoint NU410740 may experience an intermittent vibration with a light engine load between 20-35 mph. This "wobble" condition is often described as a side-to-side motion of the front of the vehicle, similar to when a belt is damaged in a radial tire.
This condition is caused by an intermittent binding condition of the S-plan inboard drive axle joints. This binding condition only occurs while the joint is rotating at vehicle speed with an engine load. The S-plan joint will not cause a vibration on a closed throttle coastdown.
This condition may be repaired by installing revised S-plan spiders and bearing blocks in both drive axles. The spider service kit, P/N 26039083, includes one spider, three bearing blocks, and two retaining clips. Two kits are required per vehicle. The revised spider incorporates polished surfaces and the bearing blocks have been enlarged.
Use the following service procedure:
1. Verify that the condition is not caused by tire imbalance. Refer to Section 3 of the appropriate Service Information Manual for tire balance diagnosis and repair.
2. Install two service spider kits (one per axle), P/N 26039083, following the service procedures in Section 4D of the appropriate Service Information Manual.
3. During joint disassembly, it is NOT necessary to remove the grease from the joint housing. The grease can be reused during reassembly with the new spider and bearing blocks.
Parts are expected to be available on October 12, 1992. In case of limited inventory, parts will be placed on 400 control to waive VIP surcharges. Only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. However, the part will be shipped premium transportation at dealer's expense, and all other order types will be placed on back order until the 400 control is removed.
WARRANTY INFORMATION:
Operation No.: T6683
Labor Time: 1.6 hr.