This tie rod end connects the steering linkage to the front axle knuckle, translating rotational input from the steering gear into the angular movement of the wheel assembly. It is the pivot point on the drag link or center link that allows the knuckle to turn. Wear at the ball joint socket produces free play in the steering, which manifests as a wandering front end and uneven tire wear. The original-manufacturer component is machined to the same taper and thread geometry as the steering arm it seats into, so no shimming or adapter sleeves are required during installation. On reinstall, tighten the castle nut to the specified torque and install a new cotter pin.