I've had the car for getting on to 9 years and have autocrossed it every year but this one. I've had 2 co-drivers for 3 years but only attend local events (8-10 per year). Late last year, I found two lug nuts missing on the right rear and ended up deciding that I must have forgotten to torque them after the last change. I changed to all-season tires for the winter and had no problems although I didn't drive it much. Changed back to the summer wheels/tires about a month ago and remembered to torque each wheel. This past week, my son used the car for a ~4 hour drive, mostly highway, and came back with a loud click. Turns out the left rear had one nut that wasn't touching the wheel and all the others somewhat loose. The left front also had loose nuts. All have been retourqued and the car is quiet. I'm going to compare my wrenches and have started buying new nuts.

Now for the real question - have any/many of you found that the studs need replacing after track/autocross use? I'm seriously considering the need on the theory that the frequent changes along with stresses from many autocrosses on R compounds have caused the studs to change their characteristics and normal torquing won't keep the nuts tight. It's (semi-)interesting that this started happening all of a sudden.

Thoughts/comments?

 

my wheel studs stretch after 2 years of autox. the threads actually pulled out and chipped. i replace all studs with forged extended studs and Kics lugs.

i used to torque to 100 ft/lbs, now i only torque to 90 ft/lbs.

 

Wrong-diameter centering rings on the wheels? Make sure the wheel is properly seating against the hub.

Regarding torques, there is absolutely no reason to torque beyond 80 lb-ft (factory spec).

 

I torque to 80 as well... plenty. Never experienced this..

 

I also tq to 80 ft-lbs

 

I also torque to 80 ft and have never had any problems. For some reason lots of autoXers/track folk I know seem to think that adding another 10 lb/ft or so will make things more secure but I never found it to be an issue as long as you use a torque wrench to the factory specs.

 

i just feel that factory torque specs is designed for factory size wheels and street tires. wider wheels and R-comp tires create more force at the hub. i've never heard of wheels coming off but i guess i just feel more secure with a little extra torque on the lugs.

 

You'll be more secure on lugs/studs that haven't been overtightened repeatedly!

Any increased sense of security tightening them beyond 80 lb-ft is false.

 

^ I agree that overtightening the lugs/studs would only make the problem worse. I would replace the studs and nuts and torque them to 80 lb-ft.

One thing I'll add, since it's sorta related. I had a brake job done by a mechanic that severely overtightened my brake bolts (probably on the order of 100+ lb/ft), then (realizing I would have to start swapping brakes for every event) I had someone teach me how to do a brake job, and he also used huge amounts of force tightening those bolts too (I nearly broke my arm trying to get them off)!

Since then, as I had been doing my own brake jobs, and I noticed that some of the bolts don't tighten as crisply as the others, but didn't really pay any attention to it. Then as I was swapping brakes for a track event a week ago, the bolt snapped in half as I was tightening it. I was able to borrow a bolt and pin from my friend's girlfriend and made it to the track. Then when I was swapping brakes back (to street setup), I noticed another bolt was stretched and narrowed. I made a mental note: order new bolts and pins. Then as I was tightening that one, it snapped as well.

I have 8 bolts and 8 pins on order, as well as all the bolts and washers that are needed to replace brake lines and brake bleeder screw (as the overzealous mechanic also overtorqued those). I also ordered a 14" torque wrench and will torque all the individual brake bolts to spec from now on. I figure when swapping brakes, wheels, etc back and forth it is very important to use proper torque specs and consider these things as wear items. If I were you, I'd just replace the wheel studs as well as the nuts.

 

jguerdat Posted on May 19 2009, 02:11 PM
Were those wheels recently painted / power coated?
Is the part of the wheel that faces the hub clean, no rust on the hub?

IMO: use this on the threads to make sure the torque is going where you want it.