I believe rotors ate "turned" by cutting the surface on a special lathe to ensure the surface is almost mirror-smooth flat and falls within a specific run-out tolerance. Limits are set to a minimum thickness that the rotors can be cut down to. MB discourages the practice but many have done it without adverse effects.

Rotors are turned on a lathe that is designed specifically for the purpose. Any automotive machine shop and brake shops have them.

As far as this vibration goes, I would be willing to bet that all these rebalances that did not remove this problem were done by putting balance weights ONLY on the inboard rim lip. The tire stores commonly will not put weights on the outboard lip because they have scratched a wheel at one point or another and been chastized for it.

These suspension systems are nimble and a dynamic imbalance will cause a vibration at high speed.

To correct this, find someone who will properly balance with a computer balancer and put weights inboard AND outboard. In 9 cases out of 10 this will correct it.

I got so frustrated with the tire stores that I bought a used 1001 Coats computer balancer, and now every car I have is silk smooth. Using the balancer is not rocket science, I could teach a high school kid how to use it in thirty minutes. The problem is that they always want to static balance which actually aggravates the dynamic balance.

Have a great day,

Larry, believe it or not, I think my woes with vibration on my CLk55 and 19" SSRs are finally over. And guess what fixed it...a Coats. I had been to 2 shops, both with GSP9700s, back and forth to both at least 3 times. I had almost given up and was getting ready to E-Bay the wheels and a wrench friend who is really a Porche specialist asked to take a shot at it. 2 wheels had too much weight on them. All of them were off by about .2 oz and placement was off by a few mm. He said what happens is when they put weights on 1 side then spin it again, if the computer says too much weight was put on, instead of taking it off and putting on less, they would just compensate with weights on the other side, and so on, and on...1 wheel actually had a total of about 3.5 oz. and after he was done, he had only 1.25 oz. total. I took it for a spin on a parkway at 65-75MPH and it felt smoother than at any other time with these wheels. I have to cruise with it to really make a fair judgement, then I'm posting a "closure" to my ordeal. My friend's Coats didn't even have provision for 19"s. The dial only went to 17 or 18. But again, the most important thing is still the person behind the machine. I still think the Hunter is an amazing machine but only with the right tech using it; otherwise, it's a very expensive piece of junk.

Have checked tie rod ends and entire front and rear suspension - several times - by very qualified MB mechs.

Am very frustrated with a car that was supposedly designed to run at high speeds on the autobahn, but can't handle 75 mph without shaking itself to death - and all the common responses haven't worked. Why should one have to search all over town for a special Hunter machine to align the wheels? My Honda Accord handled sustained high speeds as smooth as silk - on a regular basis. Not as fast as a MB, but it didn't need babysitting (and has 265k miles vice 249k for the Merc).

Just got back from a run down I-95 to NC this weekend - same story. I'm afraid I'm going to bail out of the three-pointed star ranks.

Joe,

I had a similar problem with my 300SEL. I finally went to a shop with a Hunter GSP9700 that measures road forces on the wheel and checks the tires and wheels for out of round condition and can compensate.

These cars are very tempermental about balancing. The GSP9700 was the answer for me. Go to their site for a location and explanation.

Herekee

Identical problem with my 1985 190D. same symptom, same speed (see my post " problems with 201 chassis-various"). I thought it was the flex disc. Never thought rotors...

__________________
1985 190D 2.2l Sold-to Brother-in-law
1996 Mustang 3.8l -"thinks it's a sports car"
1988 Grand Wagoneer - Sold (good home)
1995 Grand Cherokee Ltd -"What was I thinking??!!"

there are a lot of rubber parts in the front supension ,I think the rest of a well maintained 126 is pretty sturdy but 14 years is a lot of time for rubber parts and the other supension parts .I just did the front ends on
both my 126's and that coupled with well Balanced tires I have no shimmy at any speed actualy both cars seem smoother the faster you go same as a well set up Porsche or like finding out in many situations the best way to get out of trouble on a dirt bike is is to crank it on.Not sure that relates to subject........
William Rogers.........

Was bad on my 86' and took care of the majority of shaking. Changing the tires from generals to mich gave me a better ride but did not stop the vibration. Lastly, there's a very long thread on here where someone spent a lot of money on a lot of different repairs only to find out after thousands of $$ it was the LOWER CTRL ARM BUSHINGS. I have a similar vibration. The DSL and bearing corrected a lot of it. Tis week I am also putting on the lwer ctrl arm busings and expect it to be solved. Good LUck!!