are you getting this sound from the front or rear of the truck? A while back I did some work to my rear end replacing bearings, seals, and fluid and soon afterwards I got some similar issue. I was leaving a gas station and made a turn to get out of the parking lot. Can't remember which direction, but I got some low pitch grinding sound as I made that turn at low speed. I stopped to check everything out to make sure nothing serious had occured and couldn't find a thing. Next I went to a 4x4 shop and asked a few questions about it there. Got no answer or solutions to the issue from the shop and have yet to run into this issue again. However, only one thing could possible be causing this in my opinion. Clearence in the differential between the ring and pinion. When I was inspecting my bearings, I removed my carrier. Bearings were good so it was just reinstalled but now that I think of it, the clearences could be off just enough to rarely give me this issue. Soooo... That might be a good place to start. Double check clearences if you just had your gears redone.