Happens. They’re easy and cheap to replace. Its caused by running crappy wheel nuts on and off over the coarse of the vehicle lifetime.

 

Lverano,

I'd be willing to bet that some garage monkey over torqued the lug nuts using an air impact gun, stretching the stud, then time and vibration did the rest.

If one went this route, I'd be watching the remaining 19 much more closely while you own the car.

 

Seems to be quite a lot of it lately on these forums, and I don't quite understand the sudden onset of it.

 

I saw rotor replacement suggested as a cure to repeated failure of studs. I guess because a rusty rotor/hub/wheel combo can wobble in use, stressing and shocking the lug nuts.

if you get that far, that seems worth a try.

 

Thank you for the replies. yes, the previous owner definitely had someone carelessly working on his car with the air gun in hand. I replaced 4 of these before putting the car on the road. These studs were abused.

 

I replaced 4 of these before putting the car on the road. These studs were abused.

Four is not just an isolated incident. You might consider replacing all of them; it might cost more up front, but you get the peace of mind that you won't have to be doing them piecemeal as you see more of them fail - and you probably will.

 

All of the lug studs on Lil Red seem questionable.

When working on the rear sub frame last month two of the studs were stripped. It wasn't snapped like here so I just chased it with a die and sent it along.

I always hand thread the lug nuts, run them down with an impact gun on low, and torque to 90 lb ft in a star pattern twice once on the ground.

That procedure is so time consuming I've considered investing in torque limiting bars. Something like this maybe?

I think the lug stud failures might just be an age thing.

20~ years is a long time for a bolt to hold up. Especially one where in addition to the load of the car, every pot hole, every turn, it's removed and replaced pretty much every time the car needs maintenance.

I second the "Replace all" if you plan on keeping the vehicle for more than a few years.

 

COol, those look like a nice addition to any mechanics arsenal. I wonder if MAC makes them. I like MAC tools the best. Maybe I can find a nice used set on eBay for $100.00 bucks shipped. Thanks for the idea. Although I thought I was over torquing just a little at 75 lbs. , but if you say so, then 90 lb ft. it is sir. With Star pattern as always.