Lots of vibration....

Yup. First I'd rotate it 180 degrees. Just the four rear flange bolts. Be sure to mark it distinctively each time so you know where you've been. Also check carefully at the flange, there may be an old marking that you have missed.

If it is shaking that bad, you might consider having it balanced, or replace it with a newer FMS aluminum driveshaft. Double-check the U-joints as well.

-JD

** Hey everyone, i have another problem i need some help with. I did a ** real stupid thing and took off my driveshaft without marking its ** original location. Now when im on the freeway and i hit about ** 2700-2800 RPMs, the rear of the car shakes pretty bad. So much so that ** its scary to get into that range. ** ** Im pretty sure it isnt the engine because when im just sitting still ** and i rev it up to that area, theres no shaking. It only happens in ** third gear (only have a 3 speed so third is 1:1). Im pretty sure its ** the driveshaft being off balance. Is there a way to get the alignment ** back? or do i just keep taking it off and turning it slightly till i ** get proper alignment? ** ** Thanks in advance!