I have a noise in the rear end of my 85 300d it whines when the car is jacked up when you accel or deaccel when you hold the same speed it is ok and you do not hear it on the road someone has replaced the lr axel there is alot of end play in the rt axel oil is ok 245000 mi I found this out looking for a vibration in rear

Same thing happened with my father's '87 300E. They had to replace the left rear wheel bearing. The axle has to be removed to do it. so no DIY for us. It cost us $350 at a well known indy shop.
David