Improve handling and eliminate sway bar preload with aFe Control?s adjustable end links. Sway bar preload is a scenario where your sway bar is in tension when your car is at rest. Sway bar preload affect?s how the vehicle handles making it stiffer when turning one direction versus the other. Factors like lowering springs can end up with uneven suspension heights which can lead to sway bar preload. If you have adjustable coilovers and are corner balancing the vehicle, it is especially important to zero out your sway bar preload to get consistent handling.