dckotwicki

I have an 09 C6 with14k miles and I am noticing a slight metalic "clunk" noise from the drive train. It happens when the drive train goes from an "unloaded to loaded" state. Not a major noise and I am not sure if I am concerned or not.

It has an automatic transmission.
The vehicle is not driven hard.
Sounds like there could be a minor amount of "slop" in the drive train.

Anyone else notice this?

obxchartercaptain

You might have a loose axle nut....use the search function to find numerous threads on the subject. Jack up the rear of the car....remove the tires.....use a 33 mm socket and check to see if the nut is loose. Depending on how loose you can either tighten it up(thats what I did) and see if that solves your problem and monitor it...or bring it into the dealer for repair. There was a TSB on it and if you are still in the warranty period it will cover it. Good Luck

Mad*Max

my 07 with the A6 has this sound - I have had the sound for years when I shift from D to R or R to D

Kenny94945

OP need more info.

Is it as post # 3 describes.

Car is stopped in drive, then you shift to reverse and it clucks? Or your in reverse and you shift to drive and it clunks?

j_digi454

I had the same sound and it was just fixed by the dealer. It was loose axle nuts. Incidentally, even though GM has a TSB on this issue, it is only covered under the original power train warranty and not covered under the extended warranty. The loctite used was just as expensive as the nuts ($28).

sevinn

When I had that issue, replacing the end links resolved the issue.

Phoenix1911

I has the same on my '08 Z, local dealer gave me the replacement nuts under good (TSB, but out of warranty) will as long as I returned the old ones. I did the TSB myself, took 5 mins.
Just don't keep re-tightening the old nuts. The most difficult part was finding the proper size socket

Stavesacre21

Hmm...I was always under the impression that this was part of having a transaxle with the torque tube. On the C5, they even stated and the new owners DVD that it was normal to hear the sound as this just the drivetrain initially taking slack up.

Mad*Max

BettermostCorvette

My brand new 2013 with 800 miles on it is doing the same thing so don't feel to bad.

JCtx

ALL vehicles have drivetrain lash; some more than others. But it's a necessary evil for gears to engage and disengage properly. The lash is most evident with the driven wheels on the air, be it a car or motorcycle. You can move the wheels back and forth like an inch, and hear the 'clunk clunk' as you do that. Perfectly normal. It's a lot more evident (clunkier) on manual cars, but only noticeable at slow speeds. So don't worry, and enjoy your car .

Mad*Max

it certainly makes me feel better and confirms my recollection that my car has been doing this for years

j_digi454

I agree that it is normal to have some driveline lash but if replacing and tightening the axle nuts fixed the clunk noise I was getting, it was not normal unless you say having axle nuts not torqued properly is normal.

JCtx

A loose axle nut would give you EXCESSIVE driveline lash ... which wouldn't be normal, obviously. I just said some is normal. Hard to diagnose the OP's issue over the internet .

dckotwicki

How many axle nuts are there?
How much do they cost?
Where are they located?
Some say you need to remove the rear wheels, is this true?
What is the torque spec?

j_digi454

Here is a thread I saved which may answer some of your questions. As I mentioned, there is a TSB from GM on this which is described in this thread. It's from 2007 but the problem still seems pertinent on newer Vettes as well.


http://forums.corvetteforum.com/c6-c...bly-plant.html

JRHAWK9

Just replaced mine myself a week or two ago. The axle nuts themselves are part number: 10257766 and cost me $4.80ea. There are two of them. The 36ml of Loctite 272 cost me $25. It was a piece of cake. My drivers side was tight but my passengers side was on the loose side.

Biggie G

I have this issue as well....gonna see if the axle nuts are tight.....


also The 33MM socket can be rented at Autozone and Oreillys

Bill Dearborn

Pull the hub caps off your rear wheels and you will be looking directly at the axle nuts.

Bill

Mad*Max

and it is very easy to pull them off with your GPS' suction cup