Pintobay

I have a 2006 Z51 - 6 SPD - that I bought new at Kerbeck Chev. The car is not a daily driver - mostly a weekend car or if my wife an I travel. It has 13,500 miles on it. For the last several years I have heard (very infrequently) a banging sound in the rear end when you start out. Also, sometimes when you went around a corner it made this odd squeaking sound that I just assumed was something with the spring or suspension. Ove the past sveral months these two noise are much more common and "seem" to be getting worse. I had a motorhead friend drive the car today and he said he thinks it's either the rear end or the constant velocity joint. I immediately looked in the warranty book, "assuming" I probably had 5 yr/50,000 mi and was shocked to see it ran out at 3 years. I am soo po'd because this has definitely been doing this since it was within the warranty.

So here's my question(s) - what have any of you experienced? Has anyone had the same thing happen? Was there any kind of a GM problem identified that sounds like this. I am sick over the thought of spending money on a car that I hardly drive and only has 13,500 miles. Our local Chev dealer probably sells one (maybe) Corvette a year so I don't even have the confidence to take the car to them. I even thought of driving to Atlantic City to have Kerbeck's look at it. HELP.

timd38

My bet is that the axle nuts are loose. The nuts are about $14.00 for the pair and take about 15 min to install. Just take the center cap off the wheels and get a 33 or 34 mm socket and a torque wrench and that is all you need.

My 2006 Z51 did the same thing.

Here is a picture of the nut installed with the brakes gone. It is the big nut in the middle of the wheel studs.

SUB VETTE

Clunking differentials are quite common due to the positraction clutches sticking. It's usually noticeable when backing and turning or on tight low speed turns, like in parking lots. The solution is usually to change the differential oil and then do a series of figure eight turns to work the new lubricant into the positraction clutches. Over the years, GM has issued several TSB's (Tech Service Bulletins) for this problem with different lubricants and/or friction reducers that were tried for remedy.The most recent of these bulletins (January 09, 2008 " 2005 - 2008 Chevrolet Corvette, Subject: Rear Axle Clunk and/or Chatter Type Noise on Turns, #07-04-20-002A) settled on using Dextron LS Gear Oil 75W-90, part #88862624. No additive is recommended any more, just use the Dextron LS 75W-90 straight. Your dealer should be quite familiar with this simple fix, and be able to look up the TSB.

My 06 did the same as yours at about 10K miles. Changing the lubricant took care of the problem and I have had no clunking, creaking, banging etc ever since. I am now just about at 30K miles. If you are interested in doing the change yourself, there is an exellent DIY by senior member Vet. Do a search of FAQ under "DIY - rear axle/differential oil change, with pics" and it should come up.

The axle nuts being loose is worth checking also. This issue came up a long time ago too. I checked mine when the car was 6 months old and found one side was improperly torqued and loose.

Hope this helps fix your problem

Njd38

I have a 2006 Z51 convertible that around 28,000 miles started making a clunking sound in the rear. Brought the car to my local dealer who was looking to turn the repair into a million dollar repair. I drove one hour away from home to Corvette Paramedics in mount holly NJ.the problem was with the rear axel lock nuts came loose. They used Lottie and torqued the lock nuts again. Also had the rear differential fluid changed to the new type dextron fluid all for a reasonable 235 dollars. The dealership wanted 250 dollars for just the differential fluid. The axel nuts should be covered under the recall notice that's available through chevrolet but have fun trying to get them to honor it.

Gearhead Jim

Unfortunately, I believe the axle nut information is in a Technical Service Bulletin, not a Recall. Therefore, it will normally be paid for only if the car is under warranty.

But I would expect the cost to be something around $100-$150 parts and labor, so it's not too bad.

You can check if the nuts are loose, or have it done, this way:

Remove center caps from rear wheels but leave the wheels on the car.
Get (borrow?) a 33mm and 34mm 6-point socket (both size nuts were used, our car actually had one 33 and one 34). Try the 33 first, if it won't fit then try the 34.
Put the socket on a wrench and try to tighten the nut a moderate amount. Don't use a cheater bar or jump on the wrench, just give it a firm twist. If either nut moves, you should have the bulletin fix performed. If they don't move, you're probably ok on that issue.