I've got a 5.7, with a rough country 2" spacer lift. My clunking was so bad that when I would drive over rough patches of road it sounded like the whole front end of the Jeep was going to fall out. After reading this thread I ordered a set of external torx sockets on Amazon (http://www.amazon.com/gp/product/B00...?ie=UTF8&psc=1). This set has the E20, but it's 3/8 drive - not 1/2 inch, allowing you to use a smaller ratchet. With a 6 inch extension, I was able to make my adjustment without loosening the bolts holding the rack to it's frame. It's absolutely amazing that a quarter turn on that one little bolt can make all that noise go away. Now my Jeep is as quiet as it was prior to the lift. Could not be happier.
2005 Dark Khaki
285/60R/18 Nitto Terra Grappler