Center support bearing & collar on a 1987 BMW 325 e30
I was feeling a vibration underneath the car and thought the center support bearing must be worn so causing the shake. I would feel it when going up a hill. Then also thought perhaps front and rear drive shaft was not installed correctly so off balance and causing a shake. Previous owner provided repairs that showed new drive shaft replaced so was thinking that. It turned out the collar had come loose and came off so caused the shake.