I suspected that, but took your post at face value.
Stock caster for the 2008 JK is +4.2°, ±0.5°, with max left/right difference 0.65°.
Messing with caster at home is best done after you get the caster angle from an alignment machine. Then you can keep track of how many degrees you change it by putting an inclinometer on a flat surface on the axle. If you keep a record of the changes you make, the levelness of the frame and floor still won't matter.
The reason you should get the initial caster angle from an alignment shop is caster can't be directly measured. It is obtained from measuring how much the wheels tip when they are turned from side to side.
2008 Unlimited Rubicon Automatic
Last edited by ronjenx; 08-25-2019 at 07:25 PM.