I've got a grinding noise similar to a metal on metal brake sound but it does it at any speed and not only when the brakes are on. All brakes are fine. I thought maybe the e-brake was worn out and dragging but they're fine. It's more noticeable at higher speeds. All fluid levels have been checked. It doesn't seem to affect overall performance. Any tips on how to narrow it down?

 

Quite possible that it's a hub going. Does it get louder/more noticeable when you're turning one direction? Does either front wheel have horizontal or vertical play (moveable with a prybar) with the wheel off the ground?

 

That's possible. I jacked it up and couldn't get any movement by hand but didn't try a pry bar. Everything felt smooth when turning the wheel. I may sit in the back seat tonight while my wife drives and see if I can tell if it's coming from the rear end. It looks like the pinion bearing could make a similar sound.

Thanks!