I have an 1982 230E. There is a constant thumping sound coming from the front that varies with the speed of the vehicle. At higher speeds the thumps all run together and are less noticeable below the noise of the engine. When I turn to the right (say, coming off of an expressway ramp) the noise is very pronounced and if I tap the brakes the sound almost disappears.

The front wheel bearings have been replaced and I've had three different mechanics inspect the vehicle and were unable to repair the problem. Please help--the car is back in the shop and I want to call the mechanic and say check the...

Thanks!

Matt