I have a '03 Expedition XLT FX4 with 55K. I am the new owner and noticed a vibration/runble in the front end that i can feel sometimes trough the steering wheel when I have it in 2wd. When I select the A4wd the vibration/rumble goes away.
Just bought it with 51k a few months ago with factory wheels still on on it. I replaced with a A/T tire and had them double check the balancing.

Any suggestions?