Noise?

[super72]

Alright, guys my 72 4x4 is making a weird noise. It sounds like metal dragging the ground. It doesn't do it all the time but, when it does do it I can turn my wheel to the right and it goes away. It comes right back as soon as I straightin up, also it slows down and speeds up with moving of the truck. I thought it was my brakes, but everything seems to be fine. And I don't see anything wearing. Got any ideas? It doesn't affect the driving of the truck in anyway. I'm stumped.