Ken89911T

At the end of the season, with just about 1.5 years on them (track only), I have had 4 (FOUR!) studs break, all within the last 3 weeks of use. Front, back, L, R,

They were from Apex, Race series, not the bullet-nose Pro series. I need to replace them, but not a whole lot of choices. Wondering what others have had (longer) success with.

LVDell

Anybody else find it disconcerting that several guys have reported studs from Apex failing?

JohnPG

I was feeling pretty good about the t.c. kline studs on my car given the reports of apex studs failing earlier this year. But when I was at VIR on Nov 3 a friend had 4 t.c. kline studs fail on his left rear on track. They all exhibited the same failure, a crack just inside of the hub about half way though the stud. Crack had been in place long enough for rust/corrosion to be evident. Another friend has a set of titanium studs, expensive, but maybe that's the way to go. I've run the t.c.'s for two years with no issues though. Next year there will be a new set of something on the car.

LVDell

I ran the BBS studs on my 6-3 and they were fantastic with no breaks during my tenure. Maybe Joe will report in on if and when he has replaced any and how the reliability has been. Now I just run the stock bolts on my 7-3

996FLT6

When studs fail they break off or come off? Never had issue with 5 lug. Do u guys think that studs being longer and all has higher chance of breaking off due it's length? I know studs way easier for wheel changes and all but stories like these makes me hesitant since I'm doing fine with regular 5 lug bolts. Mike

SH || NC

No problems with my Apex-sourced studs; I've use 2 or 3 different sets from them; I am going to track 5 or 6 times a year though; not sure what the time-out interval is...

LVDell

My guess on failure is either of 2 scenarios

1. User error (either install or over/under torque)

2. Material failure

mooty

are these NON bull nose stuff from CDOC?
if so, i ran those too.
great stuff. never failed. though i do change them out every year just to be cautious.

mooty

longer stud isn't why they break. the breakage is usually at the hub area. not all studs are designed correctly. it's more than just a stick with grooves on them. some are VERY expensive studs.

bolts have advantages and disadvantages as well. you can't ride wild offsets b/c the bolt isn't long enough.

LVDell

Those are them

85Gold

Just say NO to ti studs. I have never had a stud break on any of my cars 2 M3 and 3 GT Porsche. Running the Rennline studs right now. I am a believer that over torqueing is the main problem. When I see people come off the track and check torque I just cringe. Torque them cold to the proper torque and just drive. The only exception to my torque rule is new wheels, as they take a little time to settle in and maintain torque without changing. IMHO

Peter

himself

I've had a few wheel studs fail over the years. Everything has a life. You just need to keep an extra careful eye on the parts that see lots cycles. Like Mooty said, you should just replace certain parts before they have a chance to fail.

-td

Mikelly

Peter, That's the directions I've read on several of the stud kits we've installed on our specmiata, M3, Corvette and Datsun. You run greater risk of overtorqing them hot, which leads to failure. You can actually damage the hub as well.

Mike

deputydog95

As much as I loved the way they work, I gave up on studs. It was a hassle. Constantly coming loose and the nuts would always stick in the socket for some reason.

I know you can red loctite them, but if one does snap, good luck getting it out.

I went back to using the wheel change assist things and stock lug bolts. Its an extra step, but only takes a minute per wheel and more important, keeps the hubs from rotating away from the rotors. I have no set screws on my front rotors, and for some reason the back rotors keep snapping the set screws leaving the spacer loosey goosey.

However, with the tire assist stud things, keeps everything in place and it's pretty straight forward. I would just go back to using the factory wheel bolts without the locks.

BTW, I was using the fancy pants bullet nose race ones. And they were longish to work with stock wheels. Could have used much shorter bolts if I was only running the CCW or OZ's. Never had one break though after a full season.

acadian_dad

Had a buddy lose 3 rennline studs on one wheel this summer (an OZ). I have a theory (no proof but a theory) that some of the issues could be due to people dry torquing the nuts on the studs without antiseize.

I was using rennline studs as well on OZ's and initially I didn't use antiseize. I noticed two things. The wear on the spherical surface of the nut was NOT uniform - it was concentrated in a ring - this suggests the radius of the nut did not match the wheel perfectly. In addition, the break away torque to remove a nut seemed way too high and variable ... I suspect (again no proof) that high friction between the nut and wheel was causing potentially too little preload in the stud for a given wrench torque. Too little pre-load is bad as well and can let the stud work too much and fatigue early.

The OE bolts have that spherical washer - but if it isn't a perfect match to the wheel - no biggy, it just sticks in place and the flat top surface slides against the flat surface under the bolt head (and this interface gets antiseize ...) and its all good.

I started using antiseize on the spherical face of the nut and on the threads on a frequent basis - not every single change but most. I never had one come loose and the breakaway torque was much more rational and repeatable.

YMMV of course.