I recently acquired a 1971 280SL (113 chassis) that I recently acquired.
The car is great except that I noticed the car has a vibration that comes on
after driving about 20 miles at highway speeds. It appears to come from the
drivetrain (driveshaft) when under power as when accelerating or
decelerating. If you feather the throttle, it is minimized and if you shift
to neutral it goes away.
I have had in to the repair shop but they have not figured it out.
This is frustrating and I am afraid to drive the car any distance as I am
concerned about permanently damaging the car. Any ideas are appreciated.