But is there something special about lining up the U-joint on a stock rearend? I just replaced the u-joint and now when I tighten the caps, the driveshaft is still loose. Is there a special part number? I got the u-joint from O'Riellys so no telling what kind of u-joint they gave me...

 

Retarded...haha you told me to! Are you sure it's the driveshaft or are you feeling the backlash of the differential? Are the caps the same size as the ones you replaced? And no, there's nothing special about lining up the driveshaft.

 

Dang, beat me to it. Please explain what you mean by loose. If the caps of the ujoint are solidly bolted down, you should be fine. If you mean that the driveshaft can rotate slightly, that is normal.