I have been hearing this grinding sound coming from my rear axle. I thought that maybe it was my bearings or that who ever put in the gears screwed up. I took the tire off of the side that I hear the grind and also took off the drum. I would spin the axle and nothing. I would put the drum back on and hear the grind. I looked at the drum and it looks normal. There was no gashes or anything on it. I did notice that the bottom of the brake shoe is not smooth like the rest. Any ideas?

 

Same thing happened with my rear side and it turned out the caliper bracket had frozen up so the inside pad had been worn down to nothing and was grinding on my rotor. Have your breaks checked out.