Hello all,

I'm looking for input and possibly an answer.

My 2004 Sierra 1500 (4wd) has a funny sound coming from what I believe to be the front drivers side tire. It's kind of hard to describe - an orbiting whining sound? Not really a grinding sound but its easy to pick out beyond the regular road noise. It comes and goes with the speed of the vehicle. I've had the the wheels rebalanced (which I thought would help but did not) and have monkeyed around with the tire off the ground. It spins freely, doesn't appear to be loose anywhere and there is not any interference against the brake pads and the rotor while spinning.

Any ideas?