Help
I had the same issue.......grinding noise. Terrible sound and feeling, but took it to the dealer, and they changed the rear diff. fluid, and for some people that fixed it all together, but my symptoms came back about 2 weeks later. Took her back to the shop, and they decited to change the clutch packs in the rear end. The operation took 8.5 hours, and I am happy to say that it has been over a month, and the noise has not returned. There is a bulletin out on this, so take your car ot the dealership, and ask them to check it out for you. I am sure they will fix it, no questions asked.
Good luck.

Document ID# 1866944
2006 Chevrolet Corvette
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Subject: Rear Axle Chatter Shudder On Turns - keywords bind differential #PIP3559C - (10/13/2006)
Models: 2004 - 2007 Cadillac XLR
2006-2007 Cadillac XLR-V
1999 - 2007 Chevrolet Corvette, Corvette Z06
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The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Rear axle chatter or shudder on turns on Chevrolet Corvette and Cadillac XLR.
Recommendation/Instructions:
If this is the first complaint for this condition flush and fill the rear axle with synthetic axle lubricant GM P/N 12378261 (Canadian P/N 10953455) and appropriate amount of the friction modifier additive P/N 01052358 (in Canada 992694). See fluid amounts listed below.
Note 1: To properly flush the rear differential remove the cover and get all of the old fluid out off the differential, wipe out the residue and then reinstall the cover and replace the fluid and additive.
If this is a repeat complaint or the condition persists after the flush and fill, replace the right and left rear axle clutch packs following published service procedures.
After clutch pack replacement use synthetic axle lubricant GM P/N 12378261 (Canadian P/N 10953455). and the appropriate amount of friction modifier additive P/N 01052358 (in Canada 992694). See fluid amounts listed below.
Note 2: PRIOR TO INSTALLING THE FRICTION MODIFIER ADDITIVE FOR EITHER OF THE ABOVE REPAIRS THE BOTTLE MUST BE SHAKEN VIGOROUSLY FOR AT LEAST 1 MINUTE TO MIX THE ADDITIVE THOROUGHLY.
Once the axle fluid has been changed the car must be driven in 8 - 10 SLOW figure eights to work the fluid between the clutch plates.
Fluid capacity:
Model Year
Model
Differential Lube
Friction Modifier
2004-2006
Base XLR
1.69 qt (1.6L)
4 oz. (118 ml)
2007
Base XLR
1.95 qt (1.85L)
5 oz. (148 ml)
2006-2007
XLR-V Series
1.95 qt (1.85L)
5 oz. (148 ml)
1999-2005
Corvette ALL
1.69 qt (1.6L)
4 oz. (118 ml)
2006-2007
Base Corvette
1.95 qt (1.85L)
5 oz. (148 ml)
2006-2007
Corvette Z06
2.70 qt (2.55L)
6.4 oz. (190 ml)
Note 3: Export vehicles use 2.01 l (2.12 qt) synthetic axle lubricant GM P/N 12378261 (Canadian P/N 10953455) and approximately 150 ml (5.1 oz) limited-slip differential lubricant additive GM P/N 1052358 (Canadian P/N 992694).
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these 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 your GM dealer for information on whether your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION
© Copyright General Motors Corporation. All Rights Reserved.
--------------------------------------------------------------------------------
Document ID# 1866944
2006 Chevrolet Corvette
Document ID# 1866944
2006 Chevrolet Corvette
--------------------------------------------------------------------------------
Subject: Rear Axle Chatter Shudder On Turns - keywords bind differential #PIP3559C - (10/13/2006)
Models: 2004 - 2007 Cadillac XLR
2006-2007 Cadillac XLR-V
1999 - 2007 Chevrolet Corvette, Corvette Z06
--------------------------------------------------------------------------------
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Rear axle chatter or shudder on turns on Chevrolet Corvette and Cadillac XLR.
Recommendation/Instructions:
If this is the first complaint for this condition flush and fill the rear axle with synthetic axle lubricant GM P/N 12378261 (Canadian P/N 10953455) and appropriate amount of the friction modifier additive P/N 01052358 (in Canada 992694). See fluid amounts listed below.
Note 1: To properly flush the rear differential remove the cover and get all of the old fluid out off the differential, wipe out the residue and then reinstall the cover and replace the fluid and additive.
If this is a repeat complaint or the condition persists after the flush and fill, replace the right and left rear axle clutch packs following published service procedures.
After clutch pack replacement use synthetic axle lubricant GM P/N 12378261 (Canadian P/N 10953455). and the appropriate amount of friction modifier additive P/N 01052358 (in Canada 992694). See fluid amounts listed below.
Note 2: PRIOR TO INSTALLING THE FRICTION MODIFIER ADDITIVE FOR EITHER OF THE ABOVE REPAIRS THE BOTTLE MUST BE SHAKEN VIGOROUSLY FOR AT LEAST 1 MINUTE TO MIX THE ADDITIVE THOROUGHLY.
Once the axle fluid has been changed the car must be driven in 8 - 10 SLOW figure eights to work the fluid between the clutch plates.
Fluid capacity:
Model Year
Model
Differential Lube
Friction Modifier
2004-2006
Base XLR
1.69 qt (1.6L)
4 oz. (118 ml)
2007
Base XLR
1.95 qt (1.85L)
5 oz. (148 ml)
2006-2007
XLR-V Series
1.95 qt (1.85L)
5 oz. (148 ml)
1999-2005
Corvette ALL
1.69 qt (1.6L)
4 oz. (118 ml)
2006-2007
Base Corvette
1.95 qt (1.85L)
5 oz. (148 ml)
2006-2007
Corvette Z06
2.70 qt (2.55L)
6.4 oz. (190 ml)
Note 3: Export vehicles use 2.01 l (2.12 qt) synthetic axle lubricant GM P/N 12378261 (Canadian P/N 10953455) and approximately 150 ml (5.1 oz) limited-slip differential lubricant additive GM P/N 1052358 (Canadian P/N 992694).
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these 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 your GM dealer for information on whether your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION
© Copyright General Motors Corporation. All Rights Reserved.
--------------------------------------------------------------------------------
Document ID# 1866944
2006 Chevrolet Corvette
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