The 3rd link on my rear suspension was driving me nuts for awhile. It would squeak/grind everytime I pushed on the gas and was driving my crazy until I figured out thats what it was. The polyurethane bushings had started to dry up so I lubed them up and it hasn't come back. It does click a lot when turning and shifting, but I hear that's normal with aftermarket adj. 3rd links.
Might not be what it is at all, but it's worth spraying some PB blaster or something up there to lube it for a short while and see if that clears it up. But I agree, check your rear brakes.
Torque: It's like crack for your right foot