I know what normal pad/rotor wear sounds like (or at least im pretty sure i do), and this doesn't sound like it. The sound comes from the back side of the truck (4x4, 4.7L, automatic) and sounds more like a bus's squeal than anything (obnoxiously loud as well). I took the wheels off, looked at the pads and rotors and they're fine. Any idea what this could be? I took it to a dealership a while back and they "fixed" it- only to have the sound come back after four days. They claimed that there was something wrong with the calibration of the parking brake. I haven't even touched the parking brake since then, so I don't believe that that could be the case either. Any suggestion would be greatly appreciated. Thank you.