have a 1993 300E 2.8 and whenever I brake harder than just a gradual stop, the trans seems to thud into gear. If I hit the brakes and then give it gas again before the thud happens, it's like the trans isn't in gear and the car shakes and makes all of this horrible noise before finally shifting into gear (with a loud thud) and accelerating. I don't know if this is a trans, flex disc, or diff problem, but the thud and the other noises associated with this all come from the rear end of the car.

The trans has no other difficulties. Other than this, it shifts smooth and wonderful.

Any thoughts?