This ball joint connects the front axle steering linkage to the wheel knuckle, allowing the steering arm to pivot as the suspension moves. It transmits steering input from the drag link to the steering knuckle while accommodating the angular changes that occur during turns and over uneven ground. A worn ball joint produces free play in the steering system, causing imprecise directional control and uneven tire wear. The original-specification ball joint is machined to the same taper angle and thread pitch as the host steering knuckle, so no reaming or adapters are required during installation. Tighten the retaining nut to the manufacturer's torque specification and secure it with a new cotter pin.