Question: Axle nut(s)

[Smmmokin']

Was talking to a friend today while his Vette was being serviced and he mentioned some late model Vettes have a loose axle nut or axle nuts. I use the plural but the service adviser said there was only one, anyway there is a TSB on the problem although the SA said in his three years on the job he has only come across two cars that needed tightening and he said he can't just check for tightness the customer has to complain of a "certain banging coming from the rear."

This was the first time I'd heard of this problem, have any of you? And, if so, was the fix just tightening the nut(s)?

 

[c4c5specialist]

HI there,
THE FIX, is to simply check break away torque.
If its under a certain amount, you are to replace the nuts and torque to specification.
And Im surprised considering it only takes about 5 mins.
Allthebest, c4c5

 

[NORTY]

IIRC, the first fix was to retorque to 118lb.ft.
The second fix was to replace the factory nuts with "new" nuts and torque to 140lb. ft.
I've checked mine numerous times, and have only found the passenger side below spec. I still torque to 118lb.ft, but I'm using a product to keep the threads fouled, so it won't back off. (No, it's not a locktite product!)

 

[c4c5specialist]

That torque specification is incorrect.
It should be 160 ft lbs.
Allthebest, c4c5

 

[ldf44]

Norty,
So, what do you use to lock the threads and did you loosen the nut to apply?

 

[NORTY]

Norty,
So, what do you use to lock the threads and did you loosen the nut to apply?

I removed the nuts to apply the substance. I found that the axle isn't stretching when the nut is torqued, so it'll loosen and back off with numerous heating and cooling cycles. The brake rotor supplies the heat. Friction needs to be increased before full torque is achieved. Right now, it's a "0lbs.ft. to full torque" in virtually zero rotation. This is the problem.
If you can increase the friction between the nut and axle threads, then it won't back off as the friction will help hold it there. I've checked many cars, and all but one had a loose axle nut on the pass side. (Some were backed off a couple threads.) It doesn't seem like lots of mileage has to occur for this to happen either. Some cars had < 500 miles.
On some cars, the nut is 33mm, while later cars have a 34mm nut. My car was built Jan 20, 2006 and I have 33mm.

If the axle nuts are really loose, you'll hear wheel *noise when you drive slow.

*This noise is not to be confused with the "rearend chatter" that the 3rd member is responsible for.

 

[ldf44]

What substance did you apply? Did you ever use new nuts?

 

[NORTY]

What substance did you apply? Did you ever use new nuts?

I still have the stock nuts on.

 

[c4c5specialist]

If its inspected and repaired per GM guidelines, you will NEVER have a reoccurance of this condition.

Allthebest, c4c5