I have a 2004 Ford Escape XLT 4x4. I have been experiencing a grinding noise while driving, pretty much at any speed, and I believe it increases with speed. How can I tell if it is the wheel bearings, vs. The cv joint, vs. The axle shaft, vs. Anything else? Admittedly, I am ignorant when it comes to this, and do not want to be taken for a ride when I go to the mechanic (I am a female).