I have just started driving a 300SDL which was in a front end wreck and repaired.. ( it which a tree branch pushed back the hood and cracked/broke the valve cover, and bent the transmission support bracket in to a "v" shape among other things)
the car exhibits a vibration that shows up at around 50 MPH, but does not appear to be tire balanced related..
Could it be a bent drive shaft? And, are the 300SDL's drive shaft specific to that model? or will others work as well? any suggestions on isolating or finding proof that this present drive shaft is bent or not?