I have a 2003 ford expedition EB that I purchased a few months ago. It has 63K miles on it, and recently I have noticed these grinding/rubbing noises coming from the front end area of the truck. I had a mechanic look at it, and he couldn't find anything wrong with the tires or wheels. This loud noise seems to happen only when the engine is cold and eventually as the truck warms up, the nosie goes away. The noise also goes away if I put in 4H...Has anyone experienced this or knows what the problem is? I appreciate the help!