Originally posted by rpg52:
In my manual for a '79 GMC w/two piece drive line, they say to mark the spline so that it is installed in the proper "phase". Not sure what that means, but they said it would vibrate if it was out of phase. Good luck.
A while back I had to replace the main bearing between my two piece drive shaft. they rebuild the shaft and balanced. I didn't mark the spline, followed the advise on putting the two pieces together and to this day I still have a vibration around 40mph. I tried several different settings with no improvments. Don't know how to fix but maybe thi is your problem.
..Russ
