Clicking/metal dragging sound when tires spinning?? 98 Honda accord LX 4cyl?

This sound is not all the time but I do hear it every day on and off. When I a driving it sounds like clicking or metal dragging--front and on both sides. When I break (stop) so does the noise. I've had my car checked and was told it was my axle and had it replaced and the sound is still there. What else could this be? No mechanic that I've taken it to seems to know what it is and also the sound is never there when I go. I don't want to end up stuck somewhere b/c of this. Car drives fine outside of the sound.