I just picked up a 1999 GMC suburban with a rough country 6 inch body lift and 33in tires and i noticed when I would accelerate it would make a weird sound, I thought it might have been the differential so I drained the fluid and put brand new fluid in. The fluid was not dirty. I then looked up videos of bad diffs and they seem to make a whining sound and mine isn't. I think it could be the brakes but I'm not sure. It sounds like dragging a brake caliper across the ground. Now I'm new to cars and I'm just starting to get into them and I just wanted to see if any of you could help me out on what the sound could be.

Your best bet would be to post a video.

My initial guess is a bearing/hub failing.

Will do it'* a very faint sound so it'* pretty hard to hear on camera, doesn't help it'* straight piped either.

Drive line alignment here is crucial. My *-10 does the same thing because the engine/trans was shifted over almost 2 inches to the right and the rear axle is factory shifted to the left. I only get noise under heavy accel. On the same note, I work in a heavy duty truck shop, if air bag suspensions get misadjusted, we get drive line noise.

Are we sure it is only a body lift?

Can you snap some pictures of the overall vehicle from a few different angles as well as the rear drive shaft'* universal joints from a few feet away?

The noise does it change on acceleration,deceleration,or coasting? Does it follow road speed or does it follow engine rpm or gear changes? Is it in any particular gear or go away in any gear?