SlayerMaro

iTrader: (3)

As the thread title says - I keep breaking wheel studs. I was hoping to see if anyone had any ideas about why it's happening.

I have O.E. Concepts Chrome ZR-1's (17x11 in the rear) with Nitto 555R's on them. The wheels came with wheel studs.

Anyway, I had trouble with this the first time that I went to the track with my new setup. I got some wheel hop my first run and my drivers side rear wheel broke all 5 studs and came off. It wasn't too pretty, but it could've been a lot worse.

So I figured "Ok, no more screwing around. I'm getting ARP studs." I took the wheels off and saw that the OE Concepts studs on the rear passenger side were bent to hell. It's a wonder they didn't break too.

I got them all out and put in the ARP studs. I figured I was set now, and I wouldn't have to worry about wheel studs again.

I went to the track a little over a month ago, and had wheel hop a couple of times (on 2 or 3 out of 12 passes), but the ARP studs held up.

So I was PISSED to come out to my car this week to see that one of the ARP studs in the rear had broken! I go WOT sometimes, but I don't punish the car on the street, and I can't think of when it broke (it was in the last couple days).

All the studs that broke were pretty much chopped in half where the wheel meets the stud. What gives? Can the wheels be causing this? I know wheel hop is devastating to the studs but this last one didn't even break while it was wheel hopping!

ls1king000

iTrader: (20)

obviously the wheel hop is not helping. I think you're over tightening. Are you using a torque wrench? Recheck after few miles of driving?

leadfoot4

iTrader: (1)

Are the wheels "hubcentric"? If not, I'd consider a set of centering rings.

SlayerMaro

iTrader: (3)

Yeah, I'm using a torque wrench. Factory spec 100 ft/lbs. After a couple days I rechecked them, and they were still good. I definitely thought that was the problem at first, too.

SlayerMaro

iTrader: (3)

Hmmm...I can't remember if they are or not. I'll have to take them off and look. I want to say that there isn't a ring in there.

How do I figure out what size I need?

sspddmn

how tight are you torquing the wheels studs too? I broke a wheel stud becuz I torqued it too tight.

leadfoot4

iTrader: (1)

Take a really CLOSE look and see if there's a visible gap between the centerbore of the wheel and the OD of the "hub" of the rearaxle. If there is, you probably could use a centering ring.

The trick is getting the correct one, as you probably realize. It's easy to measure the OD of the axle, but it makes life a lot easier to measure the centerbore of the rim if you have a "telescoping gauge", or "snap gauge" as some people call them. (Or, if you know the manufacturer of the wheel, you could contact them)

With respect to the ring you need, the "ID" of the ring is the OD of the axle. I know that the F-Bods did have a brake change in '97, and I don't know if that changed the rear axle. However, my '96 Z-28 has a rear hub diameter of 2.75", so in that case, a ring for my car would have an ID of 2.75" (70 mm). The OD of the ring would then be the same as the centerbore of the wheel that was being installed.


Without a hubcentric wheel, or a centering ring on a wheel that isn't, the studs are taking 100% of any loads that the wheel/tire generate. When you get into wheel hop, those loads can be extreme.

SlayerMaro

iTrader: (3)

^^ Thank you! That's very helpful info.

sspddmn

Yeah or like what leadfoot said...or it could be the battery.

ZFSix

iTrader: (14)

This may sound stupid, but it's things like this that can cause it too.

Are you torquing them in the air or letting it down on the ground before you torque the lug nuts down? Letting it down before they are 100% tight causes stress on the studs.

Also you don't have spacers right? Spacers cause added stress as well. Other than that, make sure your lug nuts are the same thread pattern as the studs, everything is torqued down correctly (not overtightened).

jjordan

You said, I torque them to factory specs=100 ft lbs. If you are running stock studs, which are 12mm, they torque to 70-80 ft lbs max. Wheel torque has everything to do with the stud size and nothing to do with wheels or nuts. Think of it just like you do a rod bolt, overtightening causes bolt stretch, which weakens the stud.

leadfoot4

iTrader: (1)

That's funny, the owner's manual says 100 ft./lbs..................

jjordan

According to their website, ARP only recommends 86 ft lbs for their 12mm studs (when the threads are properly coated), ya think GM makes better studs than ARP?

ZFSix

iTrader: (14)

Factory GM specs are 100 ft-lbs.

wabmorgan

+1 Owners manual for stock is 100 ft-lbs.