Rear Spring ?\'s I just installed a Rough Country 4 inch all spring lift. The install went pretty well for my first one. My problem is I have some minor vibs comming from the rear. After further inspection I found that there is a 4 degree differance in the driveline angles. It seems like the caster shims that are all ready on the spring packs just make the pinion level with the ground. My Question is that if the springs were installed incorrectly (even with the shim pointing the right way) is there a chance that it would make the pinion point down or level with the ground? Here is a sketch of what my rear looks like from the side; This a pretty good representative of how everything looks. The front eye is about 4 to 5 inches lower than the rear eye and the shim is just about bringing the pinion level with the ground. If I have everything right, how do I go about getting new shims? Thanks in advance.