Between the speeds of 28 and 32 mph the front of my '79 240D shakes pretty bad. I rotated and balanced the wheels, checked wheel bearings for excessive play, replaced both flex discs and center bearing on the drive shaft. The car drives pretty straight, and rides smoothly at all other speeds all the way up to 75 mph.
One other odd thing is that I some times get the same shake when the car is going about 10 mph with the brake on, but it brakes smoothly at higher speeds, so I think the rotors are fine.
The shake also occurs while the car is coasting in neutral. Any ideas? Thanks,

Otto