kcobean

Right front tire has been leaking air so I took the car to a local tire shop to find out why (I don't see any nails or other obvious damage to the tire or rim). They called and said that the lug bolts are frozen in place and they're concerned that the bolts may snap when hit with an impact wrench. I figure they have to come off sooner or later so I told them to hit them with some PB Blaster and let 'em sit for an hour and then just drive 'em off.

Anyone ever snap a lug before?

Why are rusting lug bolts so common to Mercedes. I did a Google search for "rusting lug bolts" and almost every search result pointed to a Mercedes forum or related site.

87geeinn

It would take considerable force to snap a lug bolt and would be concerned for the tool (i.e., impact driver and socket) breaking before the bolt....but anything's possible.

You can get little plastic caps that go over the bolt heads on eBay for around $2 shipped. They come from China so don't expect them for about a month but they look nicer than the rusty bolt heads.

hayseed

iTrader: (2)

buy some pb blaster and spray it on the lugs bolts as best you can without getting on the rotors and pads - do it for a couple of times/days - use a breaker bar and try to loosen

kcobean

They got the wheel off without any issues (and found a plug from the previous owner that is causing the leak). Just to see how bad these lugs were, I put an impact wrench on the other three tires at my shop and it wouldn't loosen a single bolt. So, I broke out the 3 foot breaker bar and went to town. Not a one of them were rusted, but all were ridiculously overtorqued. Argh.

I took a wire brush to every bolt to clean up the threads, applied a thin coat of anti-seize and retorqued to 100 ft-lbs. I also cleaned up the hubs with the brush and put a very thin coat of anti-seize on the fronts because the front wheels were stuck to the hubs. While I had the wheels off I gave everything a good look over. These really are neat machines.

tw2

My lug bolts were extremely overtorqued also, took a huge breaker bar. Luckily I was at home in the garage. For previous Benz I have purchased chrome plated bolts, they look a lot nicer.

Davednconfused

Just as an FYI, lug bolts should be torqued to about 80-85 ft/lbs.

kcobean

bbirdwell

You should be advised the over-torquing of the lug bolts may have caused them to exceed their "elastic" limit and undergone "plastic" deformation; you run the risk of the bolts backing out in the future. In this situation, it is recommended you replace the bolts. (Perform an internet search on "bolts elastic deformation".)

Your situation is why I carry my torque wrench with me to the tire shop; I allow the tech to snug the bolts but I put the final torque on them.

mobster600

Heat will do it......shield off the rim and take a torch on low flame