ChefMark

While driving around today I noticed a louder than normal rubbing sound coming from the differential when making a tight turn. It almost sounded like a grinding noise and seem to be louder if traction control was off. Has anyone else ever had this noise? It's a 08 with less than 6000 miles

spin-doktor

had that issue with a 2006 C6. The diff would make a rubbing/grinding kinda noise when making tight turns or going around a cul-de-sac. Dealer drained diff, and replaced fluid with revised friction modifier and all was well after that, no more noises.

Gman in NC

Same here. There is a TSB on this issue. Mine has been fine for over two years now.

C6~Missle

Have your dealer do the following TSB's :

axle nuts
diff noise

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Rear Differential:

Document ID# 2048181
2005 - 2008 Chevrolet Corvette

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)

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).

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

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

Models: 2004-2008 Chevrolet Corvette and 2004-2008 Cadillac XLR
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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.
Parts Information
Part Number.....10257766
Description......Nut
Qty................2 (one per side)

Warranty Information: Labor op F9712 0.3 hr.

RicK T

The rear end chatter has been less prevalent with the '08's but some still have a problem. I don't know why, maybe the earlier builds. Anyway here is the latest TSB in case you want to talk to your dealer service:

http://forums.corvetteforum.com/1564283516-post6.html

turmat

Sounds very familiar. There is a number of TSB's for it and GM seems to have come up with a cure. After 3 tries, mine is now OK. Check the sticky FAQ for details on rear end chatter when cold.

EDIT: Man......you guys are quick and I am a slow typist. What the guys above me said!!!!

ChefMark

Is it safe to drive or should I take it in on Monday?

larrymcgraw

Safe to drive. My wife's 2006 has been in for the issue several times. Unfortunately, still not totally corrected, as I still have the diff chatter on cold days.

dennie owens

Same thing on my 05 in the cold-advise from the forum was correct and have not had the problem again-replaced the fluid

*FAÇADE*

Below is the updated TSB on this condition that utilizes the new DEXRON® LS Gear Oil 75W-90, P/N 88862624.

ChefMark

Thanx, Guys

restless

I had a hopping like a 4x4 at low speed tight lock turns,, dealer did the fluid change for the second or third time,,then ended up changing whole diff assy.. when it didn't fix w/fluid change,,that was november ,, will know more when I take it out of storage..

C-INRED

Take it to an empty lot and do a number of low speed tight turns in both directions after getting the fluid change. This helps circulate and work the new fluid into the clutches and increases your chances that the fix will work. See #14 on the above TSB. My dealer did not do this but did mention it to me. I've had no noise since having the fluid changed out.

Red Rochester