Hey all,
I'm having a strange problem with my driver's front wheel: under spirited autox driving, this wheel starts to work loose. In fact yesterday it got so loose in my 5th run I had to abort because I thought that tire was blown. God-awful noises andwobbling. Got back to the paddock and found that it was loose on all 5 lugs, about 3/4 turn on 3 of the 5!

This wouldn't be so alarming on some people's cars, but I know I do my mounting correctly and I tighted all of the wheel's lugs before leaving the house and again in the paddock before my runs. And it's the 2nd time it's happened: first time was also when autoxing and I had to abort my last run then, too. The interesting part here is that these are different wheels, at the same position. Thus my original question: could the hub be warped or otherwise tweaked?

I've never run up a curb or otherwise damaged the car at this position, so I don't know why it would be happening now. I did just get new rotors a few months ago, and both problems have been since then. Is it possible that the new rotors are causing something strange to happen, wiggling the wheel loose under pressure?

Thanks for any help/guidance/suggestions you can offer me on this. I need to make sure I don't damage another wheel.

 

Anyone? Fry?

 

the factory wheels have "inserts" (steel i believe) in the holes for the lug bolts. this gives the nuts something other than soft aluminum to tighten against and create the friction which holds things together. if you have the stock rims check to see that you haven't lost any of these inserts. if you have aftermarket rims check the bolt holes and see if they also contain steel inserts. if you've lost an insert or you have rims w/out inserts you're tightening against the soft aluminum. this won't hold up - especially under auto-X conditions. the nuts will work free and give you the symptoms you're describing.

 

carquest-
Thanks for the info. My Mille Miglia wheels don't seem to have steel inserts, but maybe it's just well-integrated and I can't see it.

The weird part is that this weekend's autox course was pretty easy on this position - at least compared to the passenger front position. If anything, I would have expected the passenger front position to get abused and undergo the problem. However, the same hub/position as the previous incident experienced the "failure." And the other position is fine.

 

You might want to make sure you don't have something stuck to the hub that would prevent the wheel from seating properly.

 

You might wanna slow down on the Auto Xing too.

Atleast 'til you find out what's going on.

 

if the wheels don't have steel inserts AND you're tightening against a softer aluminum it's about the amount of friction you have between the base of the lug nut and the threads of the nuts & bolts. when you tighten things down you cause the base of the nut to squeeze against the rim. this applies upward force against the threads of the nut which squeezes agains the threads of the bolts. in order for the nuts to stay tight the friction has to remain high enough.

several things can affect this. vibrations in the wheels. high thermal gradients (temperature differences) in the wheels/hubs/lug bolts, etc. microscopic motion between the wheel and lug nuts during acceleration/braking. push/pull stress loads between the top and bottom of the hub and wheel during heavy cornering. the trick is to make sure you have solid metal in both the lug nut and wheel where they meet. when the friction breaks down the lugs back out.

try finding a whee/tire shop that caters to drag racers &/or road racers. i'll bet they can tell you why the lugs are coming loose. and how to correct it.