Yes the RC lift came with shims on the springs to fix the pinion angle, I'll check to see if its the front in the morning, I'll post some pictures of the angles today as well (once there is light outside)...I am pretty sure that the rear drive shaft does not line up parallel with the transfer case even with the TC drop...so I'm guessing thats where the fix has got to be...so Bounty, this sounds less like a serious $$ problem and more like an alignment?
You have the 2 options; cheap and lose ground clearance, or $$$ and get the best for the rig... I had the same problem when I lifted my Jeep, and ended up getting the SYE and CV shaft, and now have no vibes. But you can align the angles of the TC output and the pinion, and the vibes should go away (as long as you use the TC drop and make sure the DS is not binding).
This is what you want to achieve:
Now, if you do decide to go with the CV DS, keep in mind that you need to change the rear axle's angle to get rid of the vibrations. This means getting new spring perches (ussually about $15), getting the old perches out, and welding the new ones in place. In the case of a CV shaft, you want the angles to be like this:
By the way, in case of the CV shaft, you may give it 1 or 2 degrees of angle for the axle, as when under load, the axle will rotate in the direction opposite to the wheels (axle warp) and then the DS would line up perfectly.
Personally, I recommend the CV shaft, but it wil finally depend on your budget. Hope this helps!
Felipe
