2005 - 2007 Corvette: Service Bulletin: Rear Axle Clunk and/or Chatter Type Noise on Turns

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Subject: Rear Axle Clunk and/or Chatter Type Noise on Turns (Drain/Refill Rear Differential Fluid and Add Specified Limited-Slip Axle Additive)
Number: #07-04-20-002
Date: (04/16/2007)
Models: 2004-2007 Cadillac XLR (Including V-Series and Export)
2005-2007 Chevrolet Corvette (Including Z06 and Export)

Condition
Some customers may comment on a clunk and/or chatter type noise from the rear of the vehicle while making turns.

Cause
This condition may be caused by slip/stick of the posi-traction clutch plates due to insufficient limited-slip axle additive. As plates slip and stick, a jumping or jerking feel occurs accompanied by a clunk noise.

Correction
Important: DO NOT remove the differential cover from the rear or the two sides. It is not necessary to flush the old fluid from the differential.

Drain and refill the rear differential fluid using the procedure listed below. Add the increased amount of limited-slip axle additive specified below.

89021677 (89021678 In Canada)
Synthetic Axle Lubricant
Quantity: 2
(3 for Z06 and Export)

1052358 (992694 In Canada)
Limited-Slip Axle Additive
Quantity: 2

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.