I fugred out what the problem was with mine. I unbolted the track bar and sway bar links and tested the steering that way to see if I could isolate the rack as the problem. I didn't make any difference in the sound. I then went to remove the steering rack and found the two mounting bolts loose! About 30K miles ago I installed aftermarket downpipes and had to unbolt the steering rack to install them. They must of just worked themselves loose. I put some blue locktite on them and retightened. Everything is great now. Steering is much smoother, no noise, and the ride is much quieter. Sure glad it was an easy fix!