I am having a real problem with the lug bolts on my '87 300SDL (factory wheels). Having had searched on the subject of lug bolts, to anti-seize / grease or not, and all the rest, I am about ready to puke! No one has addressed the apparent problem of bolt breakage & seizure. Yes, I have torque to factory specs, tried anti-seize, and still just broke a bolt trying to remove a wheel.

I recently replace ALL of the bolts with chrome bolts that seem to be about 1/3 weight less than the bent up OE. I like the look, but they are junk. Where do I buy real bolts, or how about threaded studs with either Turner style nuts or allen type ... stainless or something that is substantial that will WORK and look good.

The extra long (3.75" x 12MM x 1.50) bolts just seem to snap above the ball. Any suggestions?


- Mike

I'd recommend getting new wheel bolts from Mercedes.
If you distrust the longer bolts, like the car originally had, you can try the ones without any extra extension at all, just the head, ball, and threads. The extension is just for looks.

Gilly

Mike,

You didn't exactly say, but I'll bet none of the bolts you are breaking are factory. I can't begin to count how many 126 wheels I've removed and installed as an MB mechanic and never had a problem unless the car was last at a chain tirestore. I know the price of 20 bolts adds up, but factory is your best bet.

Good luck,
Peter

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Actually, one broken factory bolt and one replacement - neither one after a chain store visit. All were torqued to specs.

I think that I'll replace the bolts with the shorter style and find bolt cap extensions for a good look. At least if I have a breakage, I'll still be able to remove the wheel.

Any idea where to buy the extensions or proper tuner style bolts?

- Mike

Mike,

Without seeing the car I can't see where you are having the problem. I don't have a clue where to get extensions, because of running hundreds and maybe thousands of those bolts in and out, I have never had any trouble. I have seen stripped bolt holes after a chain store visit where they use big fast air guns. They turn the bolts too fast and the friction heats the threads to the point where they seize. Is your torque wrench calibrated? are you applying only about 65 to 85 foot pounds? Are the theads in some of the holes on poor condition? I always run the bolts in dry without any lubricant or anti seize. If all the above is in order, I'd go with factory bolts and I'll bet every other professionl mechanic on here would concur. Also I run the bolts in and out with a low speed and low torque air gun.

Good luck,
Peter

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Thanks for the encouraging words. I am sure that you guys are speaking from experience. All I can say is maybe my bolts / wheels / hubs are trying to make me crazy.

Although not a NIS calibrated torque wrench, I am sure that it is not grossly inaccurate, threads are AOK (thread bolts in by hand till they seat), then torque to 80 foot pounds (factory specs say 110 newton meters == 82 foot pounds).

The bolts all have broken in the extension area. It seems like they bind up in the ball to wheel seat area. Everything looks good and the bolts have broken on different wheels.

As far as factory bolts, gee at $7-8 each ...

Oh well!

Mike

Mike,

I just had another thought. It seems like you have checked everything and done everything right. It may be possible that some animal in the past used a turbine engine starter or something to install the bolts and stressed them to the shear point of the metal. I have just never seen this before, and since I don't work for Mercedes I don't have any ulterior motive for telling you that. Perhaps another set of bolts will solve your problem. Just for fun I'll post this in the techs only section.

Peter

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Hi Peter,

Thanks for the help.

- Mike

I run Independent Mercedes in New Orleans.I have been in business for myself since 1976. this has been a very common problem with the w126,one of my favorite Mercedes models, since they switched to the new look mag from the orginal 15" mag with exposed bolts about 1982.
They always break just under the head of the bolt as if the heads on this stupid bolt was orginally just welded on, leaving an inch and 1/4 of the post in the way of drilling the bolt out.I mean they all break off at the same point on the bolts.To drill this bolt out then you need a set of cobalt very hard high speed drill bits and you must drill through an inch and 1/4 hard steel bofore you start drilling through the part that holds the wheel on.