ok so i finally figured out why i had all this noise in the front driver side of my truck. the u-joint is hitting the grease fitting for the upper ball joint. now to the second part of the problem. why is the u-joint spinning in the first place? its in the auto position, and for some reason its still engaged in 4wd, but only on the driver side. it still spins even when i take the hub out. wtf? i dunno where to start!