OME and scrapping

[Cruiserhead05]

I got the 80 back wednesday with the new ome heavy and 285's. I'm in love with it. its awesome but just today i notices a scrapping sound or grinding sound at low speeds. 30-50 mph when i lightly press the gas pedal or let off of it. I just recentyl fixed the whole "highway vibration" problem, neede new pinion seel and u-joints tightened, i believe. any ideas what this could be?
Also, i just added my diff breather extension today, i dont think that is involved though.

 

[Josh83]

Does the sound vary with your speed, or is it constant? I had a rubbing when I turned right only at any speed, that changed with speed. Turns out when I put the jack under the caliper to articulate the axle I wasn't careful enough and bent my backing plate some. It wasn't touching at rest(even when turned right) but when I was moving it was. I bent it back out and all rubbing went away.