Front End Noise

I have a 1999 K1500 Suburban. It makes a knocking noise when coasting at lower speeds. The noise will go away when under load or when the brakes are applied. I thought at first it was a loose brake caliper flopping around. I changed out the pads and rotors (it needed it anyway) and it still makes the noise. I thought it could be a CV joint, I inspected it and it all looks good. To summarize….. It only happens when coasting, it seems to be dependent on speed, it is coming from the left front and it will go away when the brakes are applied. Any ideas?:banghead:

I had a kind of clunk when I went over bumps in 2000. It turned out to be the lower shaft that connects to the steering box.
Is there some way to put it up on stands and see it you can get it to make the noise?