I'm having the same problem right now. It's causing my entire jeep to shake

 

The non-coil TeraFlex leveling kit is just coil spacers cut so that the front is lifted higher than the rear to level the vehicle, right?

I guess my point is, this shouldn't be limited to TeraFlex, but rather something a certain percentage of all coil space lifts see in the 2" range. Perhaps it's just the leveling kit's popularity here that makes it appear there is a correlation?