1985 745t

Lately I've been having an issue with my steering wheel vibrating, sometimes quite severely. I've tried to track down some kind of pattern to when it happens, but it seems almost completely random. (looked through teh FAQ and found nothing on this problem).

It can happen when the car is cold or when it has been run for awhile, although it seems less likely if the car has been run for an extended period (like 2-3 hours). It happens when braking, when applying gas, or when coasting down hill. It will happen in cold or warm weather, and will vary in severity; sometimes it will appear and disappear quickly, while other times it will appear and get fairly violent until it just disappears suddenly.

I've checked all my fluids, have replaced most of the bushings with PU in the past 6-10 months, and can't seem to track down a source for this. The all the tires and rims seem to be in fine shape, and I check the air regularly.

The only problem I know of that could be related is a failing upper strut mounting/bearing/whatever. Basically I get a clunk at low speeds when turning sharply and know I need to replace the mounts. Could a worsening of this problem lead to the kind of intermittent vibrations I'm experiencing?

Thanks in advance.

-rt