A Panhard rod (also called Panhard bar or track bar) is a suspension link that provides lateral location of the axle. Originally invented by the Panhard automobile company of France in the early twentieth century, this device has been widely used ever since.ts major disadvantage is that the axle must necessarily move in an arc relative to the body, with the radius equal to the length of the Panhard rod. If the rod is too short, it allows excessive sideways movement between the axle and the body at the ends of the spring travel.