jax13553

need help with my rear caster angle. i have a 6.5 inch lift and needin to know what degree shims are the best to run.....it already has a 1 inch t-case lowering kit

Howler_GT

To determine the best angle shim to use you need to find the angle difference between your TC tailshaft and the rear axle pinion.

A magnetic angle finder works best. Only drawback is you will need to remove the driveshaft.

Since the number you are looking for is a "difference" having your XJ on perfectly leel ground is not a necessity.

Put angle finder on the tailshaft of TC (or yoke if a SYE is installed)
Note the angle number.
Do the same for the rear yoke.

Subtract the smaller from the larger.

Optimum (IIRC) is somewhere in the 5-7* range. Chime in if this is incorrect.

EXAMPLE:
IF you have an 11* difference then a 4* shim is required.

Be carefull when purchasing shims as there are two types:
FLAT: For SOA (Spring over axle- like we have)
CURVED: For SUA (Spring under axle- NOT like we have)