Scretching noise from back end

[Buffalosports]

Just yesterday I noticed that everytime I turn left, this deathing sound comes from my back end. It is a scretching noise that sounds like metal on metal. This does not happen when I turn right. Nearly everytime I turn left it happens and sometimes when stopping. However, it is not nearly as loud when braking. The pads and rotors, on all four tires, where replaced within the past 6 months so I do not think it is bad brakes. I am wondering if it is posible that perhaps one of the calipers is seezing up and the pad is rubbing the rotor when turning. I looked under the truck today and nothing seemed out of the norm. Anyone have any ideas? Thanks.