thanks for the response. the noise is loud enough that I doubt the earlier vibration could have masked it. regarding the diff, is the diff. flange supposed to line up with the trans flange in any way or are they independent? I am just wondering if I rotated one or the other by 1/3 while the driveshafts were out. would that make a difference? also, is it possible that the whine could be caused by overtightening the flange bolts on both ends or the bolts for the center bearing carrier? I tightened everything by the book, but they seemed not to be very tight, so i gave them an extra turn.

Does anyone know for sure what the sound would be like if the driveshafts were not properly aligned?

Rich Mayer
82 500 SL