andrew911

I have a question that I've been wondering about. If someone has wheels on their car that have been overtorqued by a tire shop with an air gun wrench and the wheels have been on for several years, if you loosen the nuts and re-torque is there damage that could have been already done? If it was like that for a couple years, is there a chance that now you should increase the amount of torque used relative to the factory recommendation since the nuts may have minutely enbedded into the rim or the threads over the years? Or should you use the factory torque amount regardless of how hard the nuts were put on before?

I don't know that my 911 lugs are overtorqued (it's always gone to one of the best tire shops in my area), but I'm getting a snap on torque wrench and will be removing rims on 2 of our other cars, and was wondering this as I'm almost sure the other cars are overtorqued since the other tire places tend to overtighten.

Thanks for any imput on this somewhat strange inquiry I have been wondering about it, and figured what a better place to ask the question then Rennlist!

-Andrew

WPOZZZ

If they are overtorqued, they can stretch the bolt which leads to fatigue.

psychoideas

Hi Andrew,

If the nuts are off, when you put them back on just go to the factory recommended torque.


It's hard for me to explain but they are a thread and will forever torque to the correct amount until the nut bottoms out on the stud. (will never happen as long as the wheel is there)

The only down side to them being over torqued before is, depending on how tight they were, the studs, nuts, or the threads on either may have been damaged. I doubt it though.
Just look after them from now on.

theiceman

But of course it depends on how over torqued. I think putting it back to required torqu will not pose any hazard, the problem with overtorquing is probably twisting and starining the rim. So putting it back can only help.
To be fair to everyone however I don't think there are many shops left where they jack any whell to 250lbs. These guys are quite knowledgable thses days. Remember all manufacturers use aluminu, alloy rims now and have similar 90lb torque specs.

Even air gus now have " torque sticks" which look like extensions that go on the gun and they kick back the gun so it will not overtighten. I worry more about the impact gun damaging my anodized lug nuts than overtorquing my wheels

all the best ..

andrew911

Excellent information! Thanks!

-Andrew

r911

I do not agree with this and am unsure where someone may have seen it: "they are a thread and will forever torque to the correct amount until the nut bottoms out on the stud."

I agree with WPOZZZ, except for one thing - the studs are steel & your nuts are surely Al - so the nuts will distort and pull apart first. Inspect them carefully and reuse if ok. If they feel loose (and they will anyway after decades of use) replace them with new factory ones.

Be sure to use the Porsche anti-seize on the convex portion of the nut and on the threads - sparingly. Torque correctly, and then check after 100-200 miles.

GothingNC

Here's some more info

http://forums.pelicanparts.com/showt...h&pagenumber=3

MDL

Over torquing will DEFENITLY damage an aluminum lug nut or any nut for that matter. If it was only a few lbs of overtightening it's probably no big deal. The problem is you don't know if they were overtorqued way back in the day or how many times if any, it happened. New lug nuts would be CHEAP insurance, not to mention piece of mind. I replaced mine with steal because PCA recommends it for De's Aluminum lugs kind of scare me... The good news is that the steal stud should still be in good shape because I would think the alum would be damaged well before the steal stud. When I bought the new steal nuts, I ran a dye over the wheel stud just to clean the crud out of the threads. I used a very small amount of anti seize on the shoulder of the nut only, not the thread. torque to 96 ft pounds and check torque after a few hundred miles and not wonder about it any more.

Dan.

Daniel Dudley

I'm sure you know that a torque wrench is never used for removing nuts, only for tightening. Also, it can take considerable force to remove even a correctly torqued lug nut after it has been on for a while, so that is not always an indicator of over torqueing.

Also be aware that the easiest way to snap the studs is by under torqueing. The shear strength is greatly enhanced by the friction of the wheel pressed tightly to the hub. Most aluminum wheel manufacturers reccomend retorquing after driving for one hour. I almost lost a wheel on one of my cars after a spirited drive following a wheel rotation at a tire shop. Four of the five studs had snapped.

I now check them using the Dudley Grunt-o-meter, which is pretty close to 80 foot pounds. It takes a double grunt to get them off later though.

andrew911

Do you think the high end tire shops use porsche or equivalent anti-seize? I wouldn't think so, but maybe I'm wrong? I've never heard of this....

r911

P AG put out a TSB on it. I doubt that non-dealer tire shops do this.

You can read more about it in my posts on Pelican, some of which reference Bruce Anderson's column where he discussed the TSB.

I don't know if 'regular' anti-seize is adequate or not - I will admit to having used it before, but I bought the Optimolly at a Pcar dealer.

I'm sure Steve W. has commented on this before. You can do some searches, or just do the above...

I agree new nuts are good insurance. I just inspect mine for the time being.

psychoideas

Hi Randy,
Yeah I said that, and I stand by it too! I did qualify it with,

My response that you quoted was in reference to andrew911’s question of

I only meant that in a given circumstance (if there had been no damage caused) it was not necessary to continually over torque fasteners that had, on a previous occasion, been over torqued. I believe that is one of the questions andrew911 was asking.

I apologize for any confusion my response may have caused,

I did start it with,

r911

Ok - I think we all agree you should not over-torque a fastener -- whether it has been overtorqued before or not....

theiceman

..yep...

Edgy01

The torque values that Porsche gives for these does not recommend anti-seize.