Justin, I reccommend that you get your TB back in your own hands, and you run through the 4WD diagnostic routine posted in our Tech Docs, here:
http://www.offroadtb.com/articles/tech- ... wd-system/That will greatly help us diagnose your system. It will also allow you to take pictures of your lift, so we can visually attempt to see if it is designed wrong. You can personally check if the lift is too high by lifting both front tires off the ground (by the frame), and spinning the wheels when in 2WD. Neither wheel should bind, and both should spin freely. While its in the air, check your upper ball joint, and ensure it's not the limiting element, if it is, it could snap. 4" is probably too high without the UCA flip.
I also moved this into the "Troubleshooting" section.