Originally Posted by 1BLKJP
If you mess around with this stuff long enough then you just start to get the feel of what looks right. When you are adjusting your rear pinion angle you want it 1 to 2 degree's beneath the rear output shaft of your TCase.
I see that tossed about a lot as the rule and I often wonder why? Personally I'd never do it that way, but there is some reason for it, eh?
Rule of thumb is just to adjust both sides the same length.
Typically, the lower mounts are much stronger and less likely to get moved around, the uppers on the other hand, are relatively easy to move around.
That said, I start with both lowers the same length, install them and roughly adjust the pinion angle with a floor jack.
Then center the axle. After the axle is centered, install 1 upper and fine tune the pinion angle.
The last upper gets floated between the bolt holes. If you jack the axle around and compress either of the joints in the arm trying to get the bolt lined up, it will wind up preloaded and stress the joint material.
Since cross caster isn't adjustable with the control arms, it doesn't make sense to try and do it.