1SLOF4

Just took my 2008 z into the dealer for the clicking sound that originates from the rear axle. The car is under the drive train warranty until Sep 2013 and only has 11k miles. Dealer says the noise is due to bad axle nuts, which I have read about on this forum. They are saying those nuts are wear items and not covered under warranty. Has anyone had these replaced under the drive train warranty? This seems like a no brainer. I don't understand how they could say nuts are wear item and not covered under warranty.

Thanks in advanced for any feedback or advice!

Brad

Sled Driver

Pardon my language, but your dealer is FOS. Axle nuts are not a wear item. I'd go someplace else if I were you.

GMuffley

briancb1

This is why I don't even bother trying to deal with a dealership for anything. They are always full of BS.

CanadaGrant

Your dealer couldn't find his **** with either hand. There are 2 service bulletins out on your car.
Rear Axle Clunk or Chatter Type Noise on Turns
Bulletin#07-04-20-002A
This involves draining and replacing the diff fluid with new GM type Dexron LS gear oil part #88862624
The second one is:
Tapping or Scraping Noise from Rear Wheel Area
Bulletin#07-04-95-001
This involves replacing the rear axle nuts, applying Loctite, and increasing the torque to 160 ft/lbs.
If your dealer is so lazy they can't even be bothered checking the service bulletins for you I would never go there again.
Everything is under warranty including the fluids and axle nuts so your dealer is either trying to steal from you or hasn't seen the ball since the kickoff.

383vett

Just torque them to 160ftlbs. I had the same clicking a couple of years ago on my 08, pulled out the handy dandy torque wrench and has been quiet to this day.

1SLOF4

I discussed with them both of those service bulletins, then didn't say the TSB number but he talked about both of those scenarios so I've give them credit for that... however they are saying the axle nuts are a wear item/not covered under warranty.

1SLOF4

I was going to do just that but I said to myself the car is still under warranty and this is clearly a drive train problem... This is the first car I've ever owned under warranty, and I guess I should have known better and just fixed it myself.

The service manager still hasn't called back and it's been over 4 hours now. Not sure if that's a good or bad sign.

Dale1990

Calling the axle nuts a wear item is odd. I'd ask them point out the maintenance interval information for it.

As to them being covered under the powertrain warranty, the GM website is a bit unclear:
Do they consider the nut to be part of the axle or part of the hub? Makes more sense to me to be part of the axle but who knows.

AzDave47

Several of our local Vette Club members have had the axle nuts replaced as warranty items after I provided them with the TSB:

http://forums.corvetteforum.com/c6-z...placement.html

1SLOF4

Just got off the phone with the service rep and they are going to fix it for free, but they say it's still not covered under the warranty. I guess I'm happy they are going to cover it, but it still seems clear to me that this is a drive train issue that should be covered under warranty and that this should never have been an issue. Thanks everyone for the inputs. If they give me any more problems I'll produce some of the threads provided saying others have gotten it covered under warranty.

RichieRichZ06

Just because there is a TSB for the issue does not automatically make them a warrantied item after the 3/36 coverage is up. TSB's are not recalls and they are only covered during the applicable warranty, after that it is the responsibility of the owner to repair. The TSB for the rear diff chatter is a prime example. GM will cover the chattering and replace the fluid under the 3/36 warranty, but after that it is considered maintenance. For those saying they had it covered under warranty, usually they ar talking about having it taken care of under the 3/36 warranty, not after your car is past the warranty period.

Most dealers will "policy warranty" the axle nuts and other simple repairs because it creates promotes customer satisfaction and those issues are usually common. In that case, the repair is covered under good will from the dealer and the owner is not responsible for the cost.

Powertrain coverage is fairly specific, but it has changed from year to year. Some years the hubs are covered and some years they are not. This is true with many components on the car so a blanket statement of "they are covered" is not always correct.

Hope this helps!

Bill Dearborn

Last year my car was clicking quite loudly on take off in forward or reverse. Sound was just like the sound I heard on my 86 Vette where the splined axle shaft was moving inside the bearing splines. Dealer replaced both axle shafts and both rear wheel bearings on the Z under the power train warranty and the problem is gone. They had to do the same on the 86. Not a common problem but it has been happening for a lot of years across several generations.

Bill

Phoenix1911

I walked into a local dealership (in Canada to boot), explained the problem, gave him the TSB and part numbers for the new nuts. As the car is an '08 I am out of warranty and had every intention of spending the $40 but the service manager said he had them in stock and would warranty it under good will. I said I would save him the shop time and he agreed as long as I promised to bring the old nuts back.
It cost me a $2 for the red loctite, $8 for the socket and a day of driving (as the car has to sit for 24hrs per the TSB), then a stop at the dealership to drop off the old nuts.
Remember to snug them to 160lbs.
After the procedure the knocking/clicking noise was totally gone! Thanks CF!

1SLOF4

RichieRich I understand TSB's are not automatically covered unless you are under warranty. I don't expect them to change my rear end fluid. I've read the warranty and it makes very specific exclusions for the drive train warranty. To me, from a systems engineering perspective: the warranty says it covers the "power train" which to me is all components that make up/have a role in that system. Of which all should be covered besides those specifically excluded in the warranty. That's just my take on it. I know this is a moot point and again I appreciate everyone's inputs! And as you mentioned it looks like the dealer/GM is going to cover it out of good faith/customer relations/satisfaction.

Thanks again everyone for the feedback!
Brad

2k Cobra

By the time they got done blowing smoke up your rear, they could have re torqued them.

Whis9

Same problem
Just ordered some wheel nuts

chasboland

I had the same problem last year. Here's what solved the issue for me.
Removed existing nuts.
Thoroughly lubed up splines with Tri-flow Teflon spray.
Cleaned threads on axles with Brakleen.
Applied Red loctite to threads.
Install NEW purchased locknut and torqued to 160 ft/lbs.
installed OLD nut as a "jam" nut, torqued to same spec.

A year later, all is quiet.

Fabio-Z06

Can anyone show pics of exactly where these nuts are? And lube splines?

I'm a picture or video guy. If I can see what people are talking about than I'm willing to do just about anything. Just need to see it once!

Bill Dearborn

No need for a picture. Just take your hands and pull the center cap off one of your rear wheels. You will be looking directly at the end of the axle shaft and the nut which is screwed on it. The axle shaft passes through the center of the hub and is held in place by the nut. The shaft and the hub have splines that mesh together which transfer power flow from the axle to the hub.

Some times the clicking can be fixed by torquing the nut but a lot of times that doesn't work. Then the nut needs to be replaced. If replacing the nut doesn't work then both the axle shaft and hub need to be replaced. The clicking indicates there is movement between the two parts and when the movement goes on long enough both parts become worn and both have to be replaced.

If you want to lube the splines you will need to remove the hub and lubricate the splines inside the hub and the matching splines on the axle.

Bill