1991 300D 2.5 Turbo: Shakes violently
When I took off, I put my car into reverse...then began backing up, I heard a loud "CLUNK"; when put it into drive, the car began shaking violently--naturally, I stopped, at this point.
After letting it idle or a bit, I shifted it back into reverse (wasn't actually moving, just shifting it into reverse); it began shaking violently again; I tried again, only in drive, only to experience the same results.
When put into park or neutral it doesn't behave in this way---the engine sounds fine and runs like a top, as always.
Any ideas what the problem could possibly be?



