Thump! low speed

[carthur]

I have a '90 300E 4mat with an ugly, new problem:

at very low speed ONLY, and ONLY if the wheel is turned left or right, there is is a loud thumping shudder, emanating from the centerline of the car. It feels as though the whole car is resisting/shuddering that motion...

To be clear, it's only at the sort of speed you get at parking, (very slow), and only if my wheels are turned at all. Straight back or forward, no problem. As soon as normal driving speed is assumed, no shudder...but I do mean shudder....

I guess I just have to keep driving above 10km/hr, and not park!

Seriously, it's not good. I only feel it if I turn the wheel either direction and either accelerate fwd or revrs...WEIRD!

Please HELP!