Stripped Studs
 

So I was installing my coils and during the install, I found almost 8 stripped and 2 broken studs. I got my wheels and new sr48 lugs mounted about 6 months ago from a pretty reputable shop. I know the oem studs aren't the best but never had this issue on my other cars, would it be due to bad install and how to prevent it in the future?

Attachment 175110Attachment 175111

It's a combination of shitty lugs, weak studs, and over torqued. To pin point the actual cause, eh? Who knows. Could be one or could be all three.

Just get some nice apr wheel studs and move on.

The stock studs are pretty weak in my opinion. I've seen these shear when torquing to OEM settings ~80lb-ft.
The first thing I did when I got my FRS was replace all of my studs.
ARP 100-7727 seem to be the gold standard. They will run you about $120 for the car and shouldn't ever have an issue.

If you want to save some money, I recommend Dorman 610-566 for $50. They're grade 10.9 and seem to have sufficient tensile strength. I've ran them for years on different cars and never had an issue when using proper torque.

I've stripped countless studs. I have a set of APR and just haven't yet installed them. In the meantime, I undertorque the wheels and check them periodically.

OEM studs, OEM lugs

I've had my wheels on and off dozens of times without issue.

I always use a torque wrench to spec, I also add a small touch of grease to the lug face and stud thread.

Been doing that for near on 40 years without ever stripping treads or snapping lugs, road, track, drags and dirt, never a issue.

im installing the 100-7728 right now. the oem studs suck. i yielded one nad broke another taking my summers tires off.

That looks like it was cross threaded and forced, probably just impacted on.

Averaging 40+ wheel swaps a season and I've never had issues... While the stock stuff is clearly not the best, it takes work for it to be as bad as this.

89lb/ft. 80 is too low and could cause issues. Also maybe an accidental typo but just in case this is randomly referenced by someone...

I've watched shops do this and cringed every time. You hand thread it first, then use the impact.

OP: You're going to have a hard time proving anything at this point, but use the opportunity to get APR studs and put them in yourself or if you have to, find a more reputable shop to help you.

Two real issues:

1) the shop probably didn't clean the threads + hand thread the lug nuts to prevent contamination/cross threading
2) SR48 are open ended lug nuts, you need to make sure the threads are clean before you install them

Minor dirt or contamination on the threads of an open ended lug nut can lead to premature failure of the stud. A simple wipe of the threads with a towel usually is good enough, but most people (and shops) don't do this at all when installing new open-ended lug nuts.

The other part is that with cheaper lug nuts like SR48, the lugs are usually coated/treated in a dip at the end of manufacturing. So there may have been loose pieces of coating that flaked off as you installed, making your problem worse.

Sorry, meant to write 85. I torque mine to 85. I didn't know the spec was 89.


I'll set my torque wrench to 89 from now on. :)