Today I push my car outta the garage for the first time since trailering it 5 hours to get chassis cert last weekend. Pushing the car out it sounds like I have marbles rolling around under my front rim covers. Pull off my covers to have find one broken stud on the drivers side and 3!!! broken studs on the passenger side front. WTF would cause this??! Studs are 3" that came with my Aerospace brake kit that have been on my car for 4 years now. I'm using acorn lug nuts with 4 lug on the front. Is there something harsh about trailering a car that would stress these like that? I have trailered my car many many times to the track, a five hour round trip, so I'm no rookie at strapping it down on the trailer. The studs literally sheared off flush with the brake rotor. All remaining lugs were tight. Any recommendations on replacement studs. Thinking of switching to a shanked lug nut too. This is the last thing I need to worry about when I cross the traps. Here are some pics....

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Thanks
Rick

 

I never broke the front studs, but did have a problem over time with the threaded holes in the hub where the studs go through actually start to round out and there was play in the stud when it was threaded in. Do you street drive the car? Have the front lug nuts come loose?

Anthony

 

The car sees about 1000 miles a season on the street.....so maybe 4000 miles since the Aerospace kit went on. I did not notice any play in the "remaining" studs. Lug nuts never loosen off in the past. What ever happened was been caused by trailering the car which I can absolutley not understand. I had my wheels off the car before I loaded it on the trailer. I'm just glad I noticed this issue and did not take the car for a rip!! I would have been riding my oil pan down the road straight into the ditch!

Rick

 

Damn, got me man, I have the drag brake setup but same basic principle. That's crazy, I had a ball joint break when the car was on the trailer, but wheel studs are another story. Good luck with it man.

Anthony

 

yah i break them on my HONDA..thats a tuff 1 dont know what would cas that..

 

That comes from overtightening.. I'm going to guess that you torque your wheel studs with a torque wrench.. And since they are 1/2 studs, I'm going to guess that you go to near 100 ft lbs..

When you torque something like a head stud, you are actually stretching the stud a little bit.. That makes the studs act like rubber bands, and keeps the clamping force on the head from loosening up..

The force's seen on wheel studs is different than what's seen by head studs.. Wheel studs don't like being stretched.. They will snap off when they are..

 

I torque to 80 - 85 ft-lbs. I agree that overtightening will cause them to break...but I'm skeptical on the fact that they were over tightened....especially that many studs. Why would they fail all of a sudden on the trailer??? That is what I don't get. Seems like it would take 10x the abuse traveling down the road over potholes and such.

 

My bud torqued the studs on his Bogart wheels.. And he had 2 of them snap off while the car set in his garage.. When they do that, it's a clear sign they are being over stretched..

My buds experience is what prompted me to answer your question.. I've seen it before.. And that what he found was the cause..

 

Appreciate the input Jeff. Like I said I just didn't think that 80-85 ft-lbs was too much. What is the correct torque spec on a 1/2-20 wheel stud?? Maybe its time for a torque wrench re-cal too on my part.

Rick

 

I'd check the rims for shit and grins. When the acorn juuust about comes into contact with the bevel, is it straight ? Maybe it looked straight after tightened because the stud was bending. Just a thought.

 

Lucky. Glad that you didn't drive it.

fwiw, I tighten 1/2" lug nuts to 55-60 on all of my vehicles. Weld pro-stars, factory cast alum, and steel. Have never had any come loose, although I always re-check the nuts holding the welds on. Sometimes they pull up a tad more after 1st drive.

Dave

 

What kind of studs came with the Aerospace kit? Could be just cheap studs and 80-85 ft/lbs was too much over time.

 

I have ALWAYS torqued my 1/2" studs to 100 ft/lbs and never have had a single problem, and I use some of my stuff pretty hard. Pretty sure you have some bad studs.

 

Agreed.

I work on big trucks for a living and we have big problems with wheels coming off. 99% of the time the studs break and it's due to being loose not too tight.

 

There is no reason to torque wheel studs to 100 ft lbs.. You're stretching the studs needlessly.. 60 lbs on them and they would never come loose..

 

I broke 3/ 4 studs on my 88 Stang. I was driving to the strip with my son in the car when it happened. Fortunately nothing happened. That was with the skinnys. Stock type lug studs.

 

Well studs are all replaced. Car is off the Jackstands sitting on its own wheels....... . Wheel nuts are are torqued to a stout 75ftlbs.........triple verified.......