My first thread on this forum...I have a 1991 535i 5sp with 109000 miles. I have read most of threads about driveshaft/center bearing/guibo problems but I am sill getting (in fact worse since repairs) vibrations. I now have vibrations in 1st and 2nd gear up to 20 mph. It is worse when the car is cold (I'm in Detroit, so it's cold), but doesn't completely go away. I used to have a vib. at around 40mph under hard aceleration and because of it have replaced the guibo, centering bushing/sleeve, the center bearing and trans mounts. Since center bearing replacement (I did this 2 months after the guibo) I have gotten the vib at low speeds I have described. I have since gone back in and re-preloaded the ceter bearing to see if that was the problem and it is better, but still there, unlike before I replaced it. My question (finally) is 2 part: should I try to preloaded it again, and if I did it wrong the first time did I damage the center bearing (only put about 150 miles on it since repl.) and should I buy another one. Other suggestions greatly appreciated.