With adjustable upper arms what way do you adjust them to gain caster up front and what way to adjust the rear?

 

Here's the process I followed when installing my lift - full CA's

1. Make sure all springs are properly seated and lower vehicle onto its own weight.
2. Front trackbar alignment and caster angle procedure.
a. Make sure steering wheel is unlocked.
b. Remove trackbar at frame end.
c. Use bottle jack to hold axle from twisting forward or backwards and remove both upper arms at the axle end.
d. Use bottle jack to set 4.5-5 degrees of caster. (DO NOT install arms yet)
e. Set vehicle track.
f. Once track is set, double check caster angle and install both upper arms at the same time. Meaning do NOT install
one upper arm, remove the jack and then install the other. This will cause unequal load on one arm, and cause the
bushings to wear out faster. Upper arms do NOT have to be the same length.

 

Front uppers:
Lengthen to decrease caster / raise pinion
Shorten to increase caster / lower pinion

Front lowers:
Shorten to decrease caster / raise pinion
Lengthen to increase caster / lower pinion

Rear uppers:
Lengthen to raise pinion
Shorten to lower pinion

Rear lowers:
Shorten to raise pinion
Lengthen to lower pinion

 

What nthinuf said!

With a lift, you want to increase caster up front, or lengthen the lowers/shorten the uppers. In the rear, lengthen the uppers/shorten the lowers to correct pinion angle.

 

Maybe I was going the wrong way with the fronts I thought I needed to lengthen the front uppers to get the caster needed. I wasn't able to get the rears on because the one hiem joint was damaged and i will have to return it.

 

Lengthening the uppers will decrease caster, and will worsen the flightiness in the steering. This is essentially what lifting a Jeep accomplishes with fixed length (stock) control arms.

 

Well is the steering more an issue on the front because won't more positive caster then increase the difference in the angle between the pinion and the drive shaft?

 

The front is a balancing act between caster and pinion. Unless you cut and turn the C's, you can't change one without changing the other. I would rather go for a better pinion angle, and live with a little bit of flightyness, than run with vibes and more chance of driveshaft/tcase issues. But everyone will have their own opinion on it.

 

Oh boy I didnt know I had to pick.

 

if you get it setup right, you don't have to choose. I have mine set I think at 5 or 5.5 and no flightiness, no vibe - can run on the freeway 90+ mph and it's stable.

I do have adjustable upper and lower CA's and adj TB front and rear.