Originally Posted by Jeepnewb38
thank you for the responses.. this is very comforting
what is Caster and pinion angle? do you know what it should be and how do i check it?
and just for clarification.. if i get a drive shaft with a double cardan joint and standard slip joint end..this will give me a good angle in the rear?
You use shims under the leaf springs to set the pinion to an appropriate angle.
A double cardan joint can operate through a greater angle than a single U-joint, so you line up the pinion with the driveshaft so the U-joint at that end doesn't have to work though an excessive angle, leaving the double cardan end to do all the ...flexing... (for lack of the proper term)
Here are a couple of site to read up on this stuff:
(read angles vs slopes, and geometry 101)
People usually modify the T-case with a SYE kit and a double cardan drive shaft.
One reason to do this is that after installing some kits, the T-case is shorter (which makes any drive shaft angles less). Another is that on older T-cases, driving with the rear drive shaft out will cause fluids to leak out. The T-case on your 1998 won't do this, so, you may be able to use a drive shaft that slips on the T-case output like a stock shaft but has a double cardan joint at one end (whereas the SYE changes the output shaft and requires a drive shaft with the slip in to the middle). (whew...)
As for CASTER, just google "caster angle" and it should be fairly clear.
Just take note that the relationship between the caster angle and the front pinion angle is FIXED (unless you pay loads of money to have the axle modified).
As you lift the vehicle, the pinion angle increases, which requires less caster angle to compensate. But again, at 2" you may be OK.
Clear as mud, eh?