A ball joint is connected to the wishbone/ control arm and is used for allowing free rotation in two planes at the same time while preventing translation in any direction, including rotating in those planes. Combining two such joints with control arms enables motion in all three planes, allowing the front end of an automobile to be steered and a spring and shock (damper) suspension to make the ride comfortable. Because ball joints take a considerable amount of stress due to repeated turns, as well as bearing the weight of the vehicle, you want to ensure that you’re buying replacement joints that are strong, durable, and made of quality materials. Some important information for selecting the correct ball joint is the fitment position (front, left/ right and lower/ upper for vehicles with a dual wishbone system) and date limitation of the unit. As car manufacturers regularly update certain peripherals and design of their models, some ball joints will only be suitable for particular models of certain years.