What Do You Mean By "rear End Chatter"?

 

If you gotta ask, you ain't got it.

Rear axle chatter is a grinding type sound that can be heard from the rear of the car at very low speed while making a turn. Frequently only happens when the differential is cold (as in not warmed up, not necessarily winter type cold). Goes away when differential warms up.

Fix is a change of fluid and additive. If it returns, then they replace the differential clutch packs.

 

Exactly Zymurgy. I would take it to the dealer anyway even if you don't hear anything.

 

exactly what i have i was wondering too

do you mean that GM knows about it and they come with a fix and do you guys have more information do you think i have to wait till my next service or take it now my car have 6000 miles is it very serious???!

 

Read first three posts of this thread:

http://forums.corvetteforum.com/show....php?t=1497063

 

thanks man very useful information

 

Here's the current PI.

Subject: Rear Axle Chatter Shudder On Turns -
keywords bind differential
#PIP3559F - (12/06/2006)

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:
Flush and fill the rear axle with synthetic axle lubricant GM P/N 89021677 (Canadian P/N 89021678) and appropriate amount of the friction modifier additive P/N 01052358 (in Canada 992694). See fluid amounts listed below.

Note 1: In some cases it has shown that a second flush procedure on a second repair visit will correct the chatter/shudder concern prior to replacement of the clutch packs.

Note 2: To properly flush the rear differential remove the left differential cover and get all of the old fluid out off the differential, wipe out the residue replace the cover o-ring and then reinstall the cover and fill with the appropriate amount of fluid and friction modifier additive.

If the 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 89021677 (Canadian P/N 89021678). and the appropriate amount of friction modifier additive P/N 01052358 (in Canada 992694). See fluid amounts listed below.

Note 3: 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

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 4: Export vehicles use 2.01 l (2.12 qt) synthetic axle lubricant GM P/N 89021677 (Canadian P/N 89021678) 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.
-----------------------

I've changed the diff lube twice and the noise seemed to get worse each time.

Looks like I'm in for a clutch pack change. The car only has 4000 miles on it! This $ucks the big one. I love you GM.

Tom

 

Thanks For The Insight!

 

Are you guys getting this covered under warranty?

 

when i asked my service advisor he said GM charges for the diff. fluid. this service is not a recall he said.

 

Warranty ... was a cool $1000.00 in parts/labor for the clutch pack replacement!

 

So we have +1 for service, and +1 for warranty, or perhaps it is not warranty until the clutch packs are deemed the problem?

 

Your service advisor is full of crap. It is a TSB, and TSB repairs are covered by warranty. Warranty isn't involved with recalls, that's a government mandated repair, and the manufacturer has to pay, whether the vehicle is in warranty or not.

 

What he said.

dentin11, sounds like you need to find a new dealer. Your is full of !

SigArms226, the fluid change is covered under warranty. I had mine done and it did not cost me anything.

 

Thanks all! I will be calling the dealer tomorrow.

 

They changed the fluid in mine, and replaced the clutch packs but it still made the noise. They ended up replacing the whole rear diff under warranty. That fixed it.

 

What is TSB??

 

Shopdog's right. My dealership was going to do the fluid replacement initially, but since they were already going to R&R a seal, they opted to replace clutches instead of having to disassemble twice. Either way, tab is on GM.

 

Technical Service Bulletin.

 

If anyone notices chatter from the rearend I highly suggest that you get it to the dealer ASAP. I noticed the chatter/noise when I backed out of my garage and turned either hard right or left. I also noticed it on any hard turns, like doing figure 8's in a parking lot. I had the car in for other warranty work and mentioned it to my Vette mechanic, who just happens to be a friend of mine. He was very concerned, but you have to tell the service advisor before the mechanic can do any work. He OK'ed the work and when my buddy got into the rearend he found that the two piece unit in the clutch was not assembled correctly, so the lube holes were not properly alligned so the lube did not circulate as it should. This is not a good thing. He reassembled the unit correctly and changed the lube to the synthetic lube and all is now fine. He said this is the second time that he has seen a car that had this problem from the factory. It was all covered under the warranty. So, if anyone does noctice the chatter get to the dealer ASAP and mention the TSB.