W210 Wheel Stud Issue
 

Have the 99 at Firestone getting the snows removed and summer rims/tires put on. They had significant difficulty with one of the wheel studs. Had a bit of difficulty following what they were saying, but basically sounds like, if it breaks off, it's really difficult to get out. They called me to explain the problem, said they were going to call the dealer to get advice, but called my indie instead and he told them exactly what they needed to do. He told them that it's a poor design and that, in cases like this, he charges an hour of labor per stud to rectify the issue.

Just thought I'd see what anyone else's experience has been...sorry I'm not able to be more specific as to precisely what the issue was. Also, they said they thought there might be a recall on the issue....but as far as I know there are no outstanding recall issues on my cars.

Edit: Found this on Benzworld: http://www.benzworld.org/forums/w210-e-class/1333329-help-lug-bolt-broken-wheel-how.html

What puzzles me is how, when the wheels were off the car just four months ago, it could be so difficult to get things apart. Their explanation (which certainly sounds plausible) is that the brutality of this past New England winter translates into lots of salt and sand and they're seeing a higher incidence of this sort of thing. With most cars, it wouldn't be a big deal...but the design of that stud makes it a real PITA.

First things first: It's not a wheel stud. Mercedes does not use them. It's a lug bolt.

And the specific problem is that it's a 12M EXTENDED SHANK lug bolt. This problem didn't exist with the 14M extended shank bolts.

The issue usually arises from the ball seat and threads freezing in the wheel and hub, respectively. And often it results from overtorquing, which Firestone (and many "chain" type shops) have been known to do. That's how it happens in four months. One bad winter isn't enough.

Ultimately what happens is that the head is turned, the extended shank deflects, deforms and then fails, breaking off above the ball seat.

If they haven't already ruined the bolt, one thing that seems to work is a a solid punch (large head/shaft) placed on the bolt head, then struck a few blows with a small sledge. That will sometimes shock the surfaces enough to break it loose.

But without knowing more, I would not be surprised if they overtorqued it last fall when putting on the snow tires.

And no, there is no recall or anything else. However, MB knows it is an issue, because you can't buy those horrible bolts any more. The replacements don't have that extended shank, so you just have the hex head directly on the ball seat. No chance to break it like that.

Good luck.

That's helpful...thank you.

Since I've got two of these cars, that adds up to 40 lug bolts altogether. I'm wondering if it might make sense simply to replace all of them.

It does indeed. It was one of the first things I replaced on my W210, though I gave them away to the guy who bought my wheels (for his W124). I hope he didn't use them. :(

Shop around; the best price I saw for a known brand was at bma parts for a bit under $3 each. There are unknown brands out there as well and you know where to find them, too. ;)

Finally, note that there are some who covet the original bolts because of styling (the head comes to the wheel surface). The new ones do not do that, so the hole is more obvious. I've never understood the desire to have looks trump performance, particularly when there is such a downside, but it does take all kinds. So you may be able to sell yours for a tidy profit, assuming it doesn't bother your conscience. :D

Good luck and happy motoring.