Steering Systems

The steering system converts the rotation of the steering wheel into a swiveling movement of the road wheels in such a way that the steering-wheel rim turns a long way to move the road wheels a short way.

At the base of the steering column there is a small pinion (gear wheel) inside a housing. Its teeth mesh with a straight row of teeth on a rack - a long transverse bar.Turning the pinion makes the rack move from side to side. The ends of the rack are coupled to the road wheels by track rods.This system is simple, with few moving parts to become worn or displaced, so its action is precise.A universal joint in the steering column allows it to connect with the rack without angling the steering wheel awkwardly sideways.

The steering-box system

At the base of the steering column there is a worm gear inside a box. A worm is a threaded cylinderlike a short bolt. Imagine turning a bolt which holding a nut on it; the nut would move along the bolt. In the same way, turning the worm moves anything fitted into its thread.Depending on the design, the moving part may be a sector (like a slice of a gear wheel), a peg or a roller connected to a fork, or a large nut.