Rack-and-pinion Steering

    A rack-and-pinion steering system also uses a steering wheel，steering column, andsteering shaft. These components transfer the driver's turning effort to gears in thesteering gear assembly.

    With rack-and-pinion, the steering wheel connects to a steering shaft and then to apinion. The pinion is a wheel with a series of projections on its edge. These projections areengaged with the serrations on a straight piece of metal tube. This tube is the rack.

    When a driver turns the steering wheel，the pinion pushes the rack to the left orright. Tie rods at the ends of the rack transfer this movement to steering arms. Thesearms connect to the spindles on the front wheels. The way the pinion and rack worktogether creates a gear reduction. The gear reduction ensures that a driver can turn thefront wheels with relative ease.

    The major components of a rack-and-pinion steering system are：

    Pinion gear - rotated by the steering wheel and steering shaft；its teeth meshwith the teeth on the rack

    Rack - long steel bar with teeth along one section；it slides sideways as the piniongear turns

    Gear housing - holds the pinion gear and the rack

    Tie-rods - connect the rack with the steering knuckles