Lee Scheeler suggested that I post this here instead of Tire forum.....
I have been experiencing a minor vibration at all speeds in '91 300E with 112k miles. Had tires re-balanced, rotated without any resulting change in problem. Shop stated that wear seemed fine all around. Yesterday I noticed some cupping on a right rear. Any one know what causes this or what the vibration problem might be. Alo can hear tire noise (almost like a thump) that changes with speed. Thanks.

It sounds as ir you may have a buldge in one of your tires. One of the belts inside of the tire could have seperated or the tire could be defective. Have them look at the tires especially in the center and sidewall.

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Benzmac:
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