that holds the tire in place and prevents the air from escaping. the bead seal is a small groove on the inner edge of the tire which rests on the wheel. when the seal is broken, the tire on the truck can be removed without lifting it. you will also need to remove the nuts. at this point, you would take the damaged tire off the axle and put the spare tire in its place. but you might find some trouble doing this because spare commercial tires can weigh up to 300 pounds. so, you may need a tool to help you lift and place the tire on the axle 