Grinding/whining/scratching noise coming from under bed
 

Hey everyone, need a little help. Im guessing it has something to do with my drivetrain. Under acceleration im getting a grinding/whining/scratching kinda sound coming from the rear under my bed. Its only under acceleration, the heavier the acceleration the louder the noise but its noticable no matter what. As soon as i let up and am at a constant speed the noise goes away, and as i get higher in gear it gets slightly quieter. I already replaced my ujoints last year, and this is a new noise compared to that. Any help would be awesome... the trucks paid off so im just trying to keep it going and fix it up.

- Brad