ft end 1988 300sel

[jsmolin]

can any one help i have a 1988 mb 300sel that at 80 mph or above violently starts to shake and at least up to 100 mph does not go away under 80 it is as smooth as glass have new shocks, springs , tie rod end assy, center link, steering dampner, even new wheels and tires and had them rebalanced problem just started out of no where so i changed everything since my wife and kids use this car car is mint no rust or anything has 212,000 miles on it dont know where to look thanks jon