1977 Mercedes 280E Bad Shakes at 90kph

Checked alignment? If the rotors are warped, it wouldn't be a little rough under brakes, you'd be lurching everywhere IME.

-mark

Haven't checked the alignment yet.Good idea though!

Check the tyres.

Daryl

if it has been sitting for 9 months and wasn't inspected by a reasonable mechanic prior to driving like you said, then be careful!

cars are great but cannot be left lying around like that without having potentially serious issues

Steve

Check tyres for lumps , then balance

Often... and it's usually from none of the above.

Jack up each wheel in turn and check the tyres for runout... either flat spots from standing or ply separation (which will cause bulges on the tread shoulders).

-- John H

If one or more suspension ball-joints or control arm bushes or tie-rod ends are badly worn, the front end can set up an oscillation (where the whole thing moves back and forth within the slop or play) which can sometimes be stopped by a sudden wrench on the steering wheel. An unbalanced tyre (for whatever reason) can stimulate this oscillation to start, or just going over a bump.

My boss had an HR which did this,..I only travelled in it once!!?

Jason

A badly unbalanced or defective tire / tyre ought to be considered, especially since the car stood so long.

Cheers for the input

I'm 99% it's a broken engine or tranny mount.

It seems to come on worse when giving it a bootful shiftting hard.