Sway bar

A sway bar is usually a torsion spring that resists body roll motions. It is usually constructed out of a wide, U-shaped steel bar that connects to the body at two points, and at the left and right sides of the suspension. If the left and right wheels move together, the bar rotates about its mounting points. If the wheels move relative to each other, the bar is subjected to torsion and forced to twist. Each end of the bar is connected to an end link through a flexible joint. The sway bar end link in turn connects to a spot near a wheel or axle, permitting forces to be transferred from a heavily-loaded axle to the opposite side.