The caster hub in your '97 Ford Explorer houses the caster bearing, basal a individual assembly. If you charge to account the hub or the caster bearing, you charge to alter both apparatus as a individual unit. Still, this is a adjustment job you can accomplish in your barn with a few basal accoutrement in about two hours after the charge to abolish the council knuckle, whether you are ambidextrous with the two- or four-wheel-drive model. more details ....... http://www.buyautoparts.com/autoparts/Ford/Explorer/Wheel_Hub_Assembly.html