The tie rod is part of the steering mechanism in your car. It is a slender structural rod that transmits force from the steering center link or the rack gear to the steering knuckle. which causes the wheel to turn. Tie rod ends have seals that protect the inside of the tie rod joint from water, dust, and sand. If the seals become worn and lose their ability to keep out these contaminants, they cause scoring and corrosion of metal surfaces, resulting in increased wear of the ball-and-socket joint within the tie rod and shortening its overall life.