BlueC615

Hello, I have a 06 z51 with about 6000 miles on it, and I have been having a noise coming from the rear end. The noise sounds like a tire rubbing against something, it creates a light vibration, it occurs between 45 to 70 mph. I know all of the wheels are in balance and the wheel bearings are fine. I have had the car in 3 times now for the same problem and they have not been able to fix the problem. I took the service manager out on the road and he also has herd the noise. He also said he has run into this on another c6 and GM ultimately bought the car back due to no fix. Now we are dealing with a GM rep, he has been out in my car with the service manager and they both herd the noise. Now the rep it telling us that he has not herd the noise and manual transmissions make noise. This is obviously not a noise that should be there. I am just wondering if anyone else has run into this problem. Thanks!

Vet

Rear axle "chatter" when cold is a very common problem with these cars. It sounds like a tire rubbing, but it is the clutch packs in the differential making noise. It happens when the car is cold and when going around turns... usually at slow speeds. Sounds like your problem may be related.

Check out the TSB:
http://forums.corvetteforum.com/show...24&postcount=2

For more differential chatter info, just do a search here. There are a zillion threads on the subject.

BlueC615

I have seen those threads, but mine makes the noise anytime, even after a good 30 mins of hard driving. It does sound like a tire rubbing, and the techs have even checked the clutch packs. Like I said it occurs all the time between 45 to 65mph, it is the most obvious at 65.

Vet

Hmmm... not sure how the techs "checked" the clutch packs. To my knowledge, you cannot get at them unless you remove and fully diassemble the entire differential which is a big job.

The noise you hear... does it only occur when making turns, or when going straight too? Does it occur when accelerating hard, or just cruising with minimal load, or when braking, or?

Do you have the original factory wheels and tires on the car? Original anti-sway bar etc? Did you lower the car? Any suspension mods at all?

If you or the techs still cannot figure this out, I'd recommend changing the differntial fluid, replace with the mineral based oil as outlined in the axle TSB. This is cheap and easy to do and who knows, it MIGHT actually help or even cure the issue... certainly can't hurt.

Changing the oil in the differential is about the only differential related course of action you can take without removing and tearing apart the differential. So it's a good initial troubleshooting measure.

BlueC615

The noise occurs all the time between 45 to 65 mph, when at minimal load, braking, and WOT. It does occur during turning also. Everything on the car is stock besides exhaust, which is not the issue, as it made the noise a week before I installed it. The techs told me they checked the rear end and it was supposedly fine.

Vet

To my knowledge (someone please correct me if I'm wrong) the clutch packs would only make noise on turns or whenever the two rear wheels are not turning at the same rpm as each other. So if you hear the noise when you are going straight, it is probably NOT the clutch packs. Not sure what it could be. Best of luck with it, and please report back to the forum with details once you solve the mystery.

70454

Would this be a bad wheel bearing?

BlueC615

Well finally got a response from GM, they finally decided to buy the car back, due to no fix. They are charging me 28 cents per mile depreciation, which I am fine with since it only comes out to be about 1600 off of what I paid for the car. Now I am thinking about a 07 Z. I hear about many problems, but nothing to terrible.

HLH

My Vette mechanic said there was a change in the rear end oil from what was originally provided. The original was without an additive and caused noise, then Vette sent out a tech note advising that the original oil needed replacing, and that an additive was needed as in previous Vettes. Check it out, but it gives you a question to ask. You have to place "Vette doctor" to often with these dealer mechanics who didn't get ALL the schools on the Vette.

2LT-Z51

WOW... from the dealer that sounds like a hell of a deal!!!

I'm not sure if i would buy the Z06 (personally) its a great race car for the street though.... the extra $$$$ is a bit to much.... i would take that money and mod my car (to my liking)

it does SUCK that you even have to make that kind of desision..... most have no problems with their cars (minor ones if they do) so it may be worth it to just get a new C6 (you'll have the new roof at least)

good luck on what ever you decide!!!!

spdnvet

Have the rear end fluid changed out by the dealer. This fixed my problems with the noise.

Vet

Thanks for the info. Was not aware that there was a TSB on this subject newer than 9-8-06.

Can someone please post the latest axle chatter TSB please.

Thanks!