Rack and Pinion is a steering mechanism in which a pinion gear on the steering shaft engages a toothed rack, converting shaft rotation directly into lateral rack travel. The rack ends connect to the tie rods, so the mechanism has few joints, little inherent lash and a direct load path from the tire back to the driver’s hands, which is why it gives more feedback and precision than a recirculating ball box with its idler and center link. Steering ratio is set by the pinion size and the rack travel per turn, and combined with steering arm length it fixes the number of turns lock to lock and the effort required. Rack placement, both height and fore-aft position relative to the front axle centerline, is a geometry decision because it determines the tie rod arcs and therefore the bump steer characteristics of the front suspension.