Hi guys, I have a 00 XJ that is lifted 6 inches. It has adjustable lower control arms on it, stock upper control arms. I was wondering if some one could tell me how to adjust my front pinion angle. I seem to have a bad vibration when using 4wd.

Extending the lower arms will rotate the pinion down and visa versa.

Got pics of the drive shaft to pinion angle?
With a 6" lift your most likely gonna need long arms for sure. I never saw anybody running stock uppers on a 6" lift.

x2 on pic adjustable short arms would be a plus or ca drop brackets

sorry for the newb question, but what are ca drop brackets?

These

control arm drop brackets i run them with adjustable arm and short arm with no probs im on 10.5 inches of lift

Pinion is Waaaaaaaaaaaaaaaaaaaay to low.

Shorten the lowers or extend the uppers.

Ok...what will that do to my alignment? Do you know what the angle should be?

Your caster angle should be 6-8 deg., steering wheel might need to be recentered.

Sorry I should have been more specific...what should the angle of the pinion be. Sorry for the confusion.

Setting the caster will put the pinion at the correct angle.

How do you measure the castor angle?

Angle finder on the lower portion of the inner C, there's a flt surface there.