A steering knuckle is a sturdy solution for the chinks in the armor located in the stock JK axle steering configuration and 4WD carries various kits and individual knuckles to remedy this. Typically comprised of heavy duty ductile iron to withstand stress, a knuckle can help you maintain steering at steeped angles and. If your Jeep is lifted, knuckles can be especially effective and top manufacturers include Crown Automotive, TeraFlex and Jeep®. Steering knuckles are for front and rear of driver or passenger sides and are customized for 2 and 4-door models. 4WD also carries high steer knuckle kits and steering knuckles made exclusively for Dana 30s and 44s.