Did you remember to loosen ALL of the bolts that go through the bushings at each end of the control arms after the lift? Then bounce the Jeep a few times and the tighten the bolts to spec while the Jeep is sitting on the ground. If you just installed the spacers without doing that, then the bushings are binding and twisted out of their normal position. I've had 2-inch poly lift pucks on mine for a few years now. No creaking from 11 to 115 degrees.