This particular system is named after the type of gears that are used. A small pinion gear, connected to the steering wheel, meshes with an extended rack gear, connected at both ends to the tie rods and steering knuckles. When the driver turns the steering wheel, it pushes the rack still left or right, thereby turning the wheels left or right.
A New Rack and Pinion In a Vehicle Restoration ProjectFor decades, the standard power-steering system has been hydraulically assisted. A hydraulic pump, the power-steering pump, uses engine capacity to generate hydraulic pressure, which is fed through the energy steering hoses to the rack. When steering can be in use, hydraulic pressure boosts the driver’s input power, making for easier steering.
Rack-and-pinion steering is somewhat different from the steering boxes we viewed in last month’s concern. Perhaps the best way to describe it really is that it combines the steering container and tie rod, or centerlink, into one unit. In addition, it mounts up front, over the car, either behind the axle centerline or in front of it. That is why you’ll hear steering racks referred to as frontsteer and rear-steer racks. Install a rear-steer unit in front of the axle centerline and the tires will go left when you steer right, in exactly the same way some steering boxes have to have their internals reversed to work in certain situations.
The steering wheel, through the steering column, is directly linked to the rack, though it could also employ rack pinion steering china universal joints, a rag joint, or a sliding joint. Inside the rack is certainly a pinion assembly that in turn moves a toothed piston, and this operates the steering gear. The tie rods are linked to each end of the piston.
The advantage of rack-and-pinion steering is that it is more precise than a steering box. There are fewer shifting parts, which makes the steering more responsive. Of course, as with boxes, there are the choices of manual or power steering. It’s also very easy to screw up your frontend geometry when adding a steering rack to an existing frontend, leading to bumpsteer, though of course this will be eliminated if 
you opt for one of the many rack-and-pinion retrofit kits we’ll get into shortly.
The steering equipment transfers Rack and Pinionthe rotary movement of the tyre to a linear movement used to steer leading wheels. Two types of steering equipment are used today, the standard gear package and the rack and pinion. The standard gear box runs on the worm gear that’s rotated by the tyre to go the pitman shaft. The worm gear consists of spiral cut grooves that mesh with a sector gear at the top of the pitman shaft. The spiral actions of the worm equipment causes the pitman shaft to move the steering linkage in a linear movement. Power steering is attained by using hydraulic pressure to assist in the rotation of the worm gear.