Rear end noises

[Hawkeye]

I have been getting more and more "clunking" noises from the rear end area on my 2007 C6. A while back I had Van Chev perform TSB (Technical service bulliten) work to replace rear end fluid, and torque axel nuts to spec. This gave some relief to noises that I thought might also be from clunking exhaust system or loose suspension. Noises got a lot worse this winter and finally I went in to Van Chev yesterday and they ended up replacing the Sway Bar links in the rear. This cured the noise problem and I am a happy camper again. I was charged for the service as my Bumper to Bumper warranty was timed out and suspension parts are not (according to them) part of "drive train" 5 year -50K mi warranty. Anyways the noise is gone. Now for some new tires---I must be driving too slow as my front tires are more worn out then the rear tires Hawkeye

[Eddie44]

I have been getting more and more "clunking" noises from the rear end area on my 2007 C6. A while back I had Van Chev perform TSB (Technical service bulliten) work to replace rear end fluid, and torque axel nuts to spec. This gave some relief to noises that I thought might also be from clunking exhaust system or loose suspension.

Noises got a lot worse this winter and finally I went in to Van Chev yesterday and they ended up replacing the Sway Bar links in the rear. This cured the noise problem and I am a happy camper again. I was charged for the service as my Bumper to Bumper warranty was timed out and suspension parts are not (according to them) part of "drive train" 5 year -50K mi warranty.

Anyways the noise is gone.

Now for some new tires---I must be driving too slow as my front tires are more worn out then the rear tires

Hawkeye

This is a common problem with C6's. I had mine replaced at about 25k and they're starting to make noise again. First set was under warranty but not this time.

[1EVLC7]

2007 Chevrolet Drivetrain coverage

5 Year 100k mile drivetrain warranty...

Chevrolet will warrant each 2007 through 2010 model year Chevrolet passenger car, light-duty truck, crossover or van for 5 years or 100,000 miles/160,000 kilometers (whichever comes first; see dealer for details) with no deductible, from the original in-service date of the vehicle, for warrantable repairs that are required as a result of defects due to material and/or workmanship to the powertrain components as listed below:

Engine

Cylinder head, block, timing gears, timing chain, timing cover, oil pump/oil pump housing, OHC carriers valve covers, oil pan, seals, gaskets, turbocharger, supercharger and all internal lubricated parts as well as manifolds, flywheel, water pump, harmonic balancer and engine mount. Timing belts are covered until the first scheduled maintenance interval.

Transmission/Transaxle/Transfer Case

Case, all internal lubricated parts, torque converter, transfer case, transmission/transaxle mounts, transmission/transaxle mounts, seals and gaskets.

Drive Systems

All internally lubricated parts, final-drive housings, axle shafts and bearings, constant velocity joints, propeller shafts and universal joints. All mounts, supports, seals and gaskets as well as any electrical components internal to the drive axle. Also covered are any actuators directly connected to the drive axle (i.e., front differential actuator, etc). Exclusions: Excluded from the powertrain coverage are all wheel bearings, drive wheel front and rear hub bearings, locking hubs, drive system cooling, lines, hoses, radiator, sensors, wiring and electrical connectors related to drive systems as well as any drive system control module and/or module programming.

...note there have been some changes to the coverage on 2010 model years.

Engine: 2010 Chevrolet vehicles

All internally lubricated parts, engine oil cooling hoses, lines and radiators. Also included are all actuators and electrical components internal to the engine (i.e., Active Fuel Management Valve Lifter Oil Manifold, etc.), cylinder head, block, timing gears, timing chain, timing cover, oil pump/oil pump housing, OHC carriers, valve covers, oil pan, seals, gaskets, manifolds, flywheel, water pump, harmonic balancer, engine mount, starter motor, turbocharger and supercharger. Timing belts are covered until the first scheduled maintenance interval. Exclusions: Excluded from the powertrain coverage are sensors, wiring, connectors, engine radiator, coolant hoses, coolant and heater core. Coverage on the engine cooling system begins at the inlet to the water pump and ends with the thermostat housing and/or outlet that attaches to the return hose. Also excluded are the entire pressurized fuel system (in-tank fuel pump, pressure lines, fuel rail(s), regulator, injectors and return line) as well as the Engine/Powertrain Control Module and/or module programming.

Transmission/Transaxle: 2010 Chevrolet vehicles

All internally lubricated parts, case, torque converter, mounts, seals and gaskets as well as any electrical components internal to the transmission/transaxle. Also covered are any actuators directly connected to the transmission (slave cylinder, etc.). Exclusions: Excluded from the powertrain coverage are transmission cooling lines, hoses, radiator, sensors, wiring and electrical connectors. Also excluded are clutch and pressure plate as well as any Transmission Control Module and/or module programming.

Transfer Case: 2010 Chevrolet vehicles

All internally lubricated parts, case, mounts, seals and gaskets as well as any electrical components internal to the transfer case. Also covered are any actuators directly connected to the transfer case as well as encoder motor. Exclusions: Excluded from the powertrain coverage are transfer case cooling lines, hoses, radiator, sensors, wiring and electrical connectors as well as the transfer case control module and/or module programming.

An Important Note about Alterations and Warranties

Installations or alterations to the original equipment vehicle (or chassis) as distributed by General Motors are not covered by the General Motors New Vehicle Limited Warranty. The special body company, assembler, equipment installer or upfitter is solely responsible for warranties on the body or equipment and any alterations (or any effect of the alterations) to any of the parts, components, systems, or assemblies installed by GM. General Motors is not responsible for the safety or quality of design features, materials or workmanship of any alterations by such suppliers.

What Is Not Covered

All the above items are not covered for damage due to accident, misuse, alteration, insufficient or improper maintenance, contaminated or poor quality fuel.

[08Z51]

Ed, Can I get my rear end clunking issue repaired at your establishment? My 08 is still under warranty. I also have another issue, seems like the belt is slipping when making hard shifts under hard acceleration. Have you heard of this before? Rob.

[1EVLC7]

Ed,

Can I get my rear end clunking issue repaired at your establishment?

My 08 is still under warranty.

I also have another issue, seems like the belt is slipping when making hard shifts under hard acceleration.

Have you heard of this before?

Rob.

[Hawkeye]

Ed,

Can I get my rear end clunking issue repaired at your establishment?

My 08 is still under warranty.

I also have another issue, seems like the belt is slipping when making hard shifts under hard acceleration.

Have you heard of this before?

Rob.

Yes....I'll find someone to take a look at your rear end.

Did not find any bulletins reguarding your other concern, but will address the issue.

I will need to take it on a vigorous road test of course to verify the concern

[1EVLC7]

So, does anyone know if the sway bar links are (or are going to be) covered by some kind of a secret warranty?

Hawkeye

[08Z51]

Cool, I am still within the 3 year 36,000 miles, but I also have GMPP Major Guard as well. I can look up the TSB on the End Links, the rear end fluid change and the Axle Nut issue. They are on the corvette forum, just need to find them. Rob.

[08Z51]

Here is the TSB info from the corvette forum.

# 07-04-95-001

#PIC4475B

#07-04-20-002A

Subject: Tapping or Scraping Noise From Rear Wheel Area (Replace Wheel Drive Shaft Nut) #07-04-95-001 - (09/26/2007)

Models: 2005-2008 Cadillac XLR

2005-2008 Chevrolet Corvette

Condition

Some customers may comment on a tapping or a scraping noise coming from the rear wheel area.

Cause

This condition may be due to the torque on the wheel drive shaft nut relaxing over time.

Correction

Replace the left and the right wheel drive shaft nut following the procedure below.

Remove the center cap from the rim.

Remove and discard the wheel drive shaft nut.

Apply LOCTITE™ 272, or equivalent, to the threads of the axle shaft.

Install the nut and tighten to the new specification.

Tighten

Tighten the nut to 215 N·m (160 lb ft).

Install the center cap to the rim.

Important: The vehicle should not be driven for 24 hours following the repair in order to allow the thread lock to cure.

Part Number

Description

Qty

10257766

Nut

2 (one per side)

Warranty Information

For vehicles repaired under warranty, use:

Labor Operation

Description

Labor Time

F9712*

Wheel Drive Shaft Nut - Replace

0.3 hr

*This is a unique labor operation for bulletin use only. It will not be published in the Labor Time Guide.

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

#PIC4475B:

Snap Clunk Noise From Front Or Rear Of Vehicle - keywords click link noise snap stabilizer stable suspension - (Sep 12, 2008)

Subject: Snap Clunk Noise From Front or Rear Of Vehicle

Models: 2004-2009 Cadillac XLR and V- Series

2005-2009 Chevrolet Corvette

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This PI was superceded to include 2009 model year vehicles. Please discard PIC4475A.

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The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

Some customers may comment of a snap clunk noise from under the vehicle. This may occur while driving or parking lot maneuvers and may be the result of the stabilizer links making noise.

Recommendation/Instructions:

Isolate the front and rear stabilizer bar links one at a time and evaluate. Replace any link subject to noise.

Note: The XLR base vehicle is equipped with a front stabilizer only. XLR V-series and the Chevrolet Corvette have front and rear stabilizers.

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

Document ID# 2048181

2005 - 2008 Chevrolet Corvette

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Subject: Rear Axle Clunk and/or Chatter Type Noise on Turns (Drain/Refill Rear Differential Fluid) #07-04-20-002A - (01/09/2008)

Models: 2004-2008 Cadillac XLR (Including V-Series and Export)

2005-2008 Chevrolet Corvette (Including Z06 and Export)

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This bulletin is being revised to change the fluid recommendation and to remove the requirement of adding friction modifier. Please discard Corporate Bulletin Number 07-04-20-002 (Section 04 -- Driveline/Axle).

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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.

Draining Procedure:

Raise and support the vehicle.

Clean any dirt from around the differential drain plug.

If not equipped with a differential cooler, remove the drain plug (1) and washer (2) from the differential.

If equipped with a differential cooler:

4.1. Using a bent tip screwdriver, remove the quick connect fitting retaining ring (3) from the quick connect fitting (4) and discard the retaining ring.

4.2. Remove the differential cooler inlet pipe from the differential nut.

Drain the fluid.

Filling Procedure:

If not equipped with a differential cooler, install the drain plug (1) and washer (2) to the differential.

Tighten

Tighten the differential drain plug to 35 N•m (26 lb ft).

If equipped with a differential cooler:

2.1. Install a new retaining ring.

2.2. Connect the differential cooler pump inlet pipe (2) to the differential. A distinct snap should be heard or felt when assembling the cooler pipe to the fitting.

2.3. To ensure the cooler line is properly installed, give the cooler pipe a gentle pull.

Clean any dirt from around the differential fill plug.

Remove the fill plug and washer from the differential.

Important: DO NOT add any limited-slip additive (friction modifier). With this new fluid (Dexron LS Gear Oil 75W-90) it is no longer required to add friction modifier. If friction modifier is added, it will cause the fluid to lose some of it's friction reducing properties as well as reducing seal life.

Fill the differential with the new DEXRON® LS gear oil, P/N 88862624 (Canadian P/N 88862625). Refer to the table listed below for lubrication specifications.

Check the fluid level to ensure it is even with the bottom of the fill plug hole to no lower than 6 mm (0.25 in) below the opening.

Install the fill plug and washer to the differential.

Tighten

Tighten the differential fill plug to 35 N•m (26 lb ft).

Important: Steps 8-13 are for vehicles equipped with the differential cooling system. For vehicles not equipped with the cooling system, proceed to step 14.

Raise the vehicle so the wheels are about a foot off the floor. Make sure the wheels can spin freely without obstruction from the hoist or any nearby items.

Start the vehicle and put the transmission in second gear. Slowly accelerate to 10 mph and hold this speed for one minute.

Turn the vehicle off .

Raise the vehicle.

Check the fluid level in the differential. Add fluid until the recommended level is reached.

Lower the vehicle.

Once the differential fluid has been changed, the vehicle must be driven in 8-10 tight figure eight maneuvers to heat the fluid and allow the fluid to be worked into the clutch plates.

Lubrication Specifications Application

Quantity

Metric

English

2004-2005 XLR (Including Export) and 2005 Corvette (Non Export)

1.72 liters

1.85 quarts

2006-2008 XLR (Including V-Series and Export) and 2006-2008 Corvette (Non Z06)(Non Export)

2.0 liters

2.11 quarts

2005 Corvette Export

1.88 liters

1.99 quarts

2006-2008 Corvette Export (Non Z06)

2.16 liters

2.28 quarts

2006-2008 Corvette Z06

2.75 liters

2.91 quarts

Parts Information

Part Number

Description

88862624 (US-1 Quart)

88862625 (Canada-1 Liter)

DEXRON® LS Gear Oil

Warranty Information

For vehicles repaired under warranty, use:

Labor Operation

Description

Labor Time

F9709*

Drain & Refill Rear Axle Fluid

0.6 hr

* This is a unique labor operation number for bulletin use only. It will not be published in the Labor Time Guide.

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.

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Document ID# 2048181

2005 Chevrolet Corvette

I'd go back to them, show them you know the TSB info, and see if they'll refund you. There's no reason that you should have to pay for a TSB fix on a car that's in warranty, especially when it didn't even fix the problem you took it in for.

.

[DrLans]

My recently acquired ‘06 C6 (44K miles) had the very unsettling rear end clunking noise upon slow speed turns. The third Chevy dealer I took it to finally did the right thing by adding the  friction additive to the rear end fluid. Noise gone! Very relieved. Cost me all of $70.00! Thank you Scott Baum Chevrolet, Clinton Illinois!!!

[HOXXOH]

If that happens again, or if the dealer added too much friction modifier to the point that one wheel looses traction, just drain and refill with Dexron LS gear oil P/N 88862624, which has the friction modifier included in the correct percentage. It was part of a GM service bulletin issued in Jan '08 and applies to all '05-'08 Vettes that had the original 2-part fluid. The new fluid factory fill started in late '07, but not all '08's in the last couple months of '07 had the new fluid.

[TheCMSH]

Yah what Tom says.  I put 8882625 gear oil in my '01 and problem solved.  I had the gear oil/friction modifier changeout twice on my C5 and it would always start the clunk within a couple thousand miles.