Front Axle - Caster and Pinion Angle

[FirstTimer]

In preparation for swapping out my axles and installing a lift I have been doing as much research as possible to make sure I do things right!  I have run into a bit of an information road block with the following question as there seems to be so many opinions and variables;

What is the proper (target) caster and pinion angle for a Jeep TJ with a 2.5" OME lift on 33's with adjustable upper and lower control arms? And is there a formula a set of guidelines or rules to follow that takes into account lift height, tire sizes, etc, should I want to increase either of those and therefore adjust my caster and pinion angle down the road?

Thanks for the assistance

[hps4evr]

if you're installing a complete kit then they usually come with instructions. if not, check the companies website or email them. with new adjustable arms they will usually say what length to set the arms. may need minor tweaking after when the alignment is done though.

[Jrama]

Plus there are numerous charts on the web stating correct control arm length for certain amounts of lift.

[FirstTimer]

Of course, I should have put two and two together.  I've done all the research for control arm length and then got into reading up on caster and pinion angle, where oddly enough there was no mention of control arm length...Anyway, obviously if you set the control arm length to spec stated by the manufacturer then you would have proper caster as well as pinion angle.

DUH!!! 

Right...?

[hps4evr]

on a jeep tj, yes.

[FirstTimer]

Thanks!

Why is it th0ugh that you can't change the caster on a lifted TJ with out adjustable control arms?  Can you do it on an XJ or ZJ? I thought they had the same front ends?

Also would it be wise to measure these things on my stock rig now as a reference just to make sure that the angles aren't way off after I set the control arms to the suggested length and bolt everything back up?

[Rubi03 jef]

Yes measure pick Tj is best.   Are u installing a big name company lift or a custom one ur building

If it's bought good chances it'll tell u what u need

If it's custom then Ya ull want to get numbers from a stock Tj then try to get as close as posible

Caster for the most part is to help center ur wheels after turnin a corner

[FirstTimer]

Its and Old Man Emu lift and Currie Johnny Joint CA

[Jrama]

-The best way to set arms, (so I've been told) is with the springs removed, bring the axle to full bump and make sure the axle is dead centered. Install the arms, and thats the ideal length ( lowers).
However I  believe this is all highly unnecessary, the lengths mentioned in your instructions should be fine . It is a good idea to measure each side of the axle to the first bolt on the T-Case skid to make sure the front axle is perfectly straight (just in case) this could cause some vibes.

-Pinion angle, the yoke should be pointing towards the output on your T-Case, I have found that close is good enough for everything I have done.

- I have ran with caster way out, 3" of lift on stock arms for a while with no noticeable effect on handling.

Do you have an sye?