Rack and pinion steering uses a gear-arranged to convert the circular motion of the tyre in to the linear motion required to turn the wheels. It also offers a gear reduction, therefore turning the tires is easier.
It functions by enclosing the rack and pinion gear-set in a metallic tube, with each end of the rack protruding from the tube and linked to an axial rod. The pinion equipment is attached to the steering shaft so that when the tyre is turned, the apparatus spins, moving the rack. The axial rod at each end of the rack links to the tie rod end, which is mounted on the spindle.
Most cars need three to four complete turns of the tyre to proceed from lock to lock (from far to far still left). The steering ratio demonstrates how far to carefully turn the steering wheel for the wheels to turn a certain amount. A higher ratio means you need to turn the tyre more to carefully turn the wheels a specific quantity and lower ratios give the steering a quicker response.
Some cars use variable ratio steering. This rack and pinion steering system runs on the different number of tooth per cm (tooth pitch) at the heart than at the ends. The effect is the steering is definitely more sensitive when it’s switched towards lock than when it’s close to its central placement, making the car more maneuverable.
There are two main types of rack and pinion steering systems:
End take off – the tie rods are mounted on the finish of the steering rack via the inner axial rods.
Centre take off – bolts attach the tie rods to the center of the steering rack.
As steering is essential for controlling your vehicle, it’s important to diagnose and repair any steering problems as quickly as possible.
The chances are your vehicle has rack and pinion steering.
Thankfully, the fundamentals aren’t hard to understand at all: it’s about turning rotational motion into linear. When you turn the tyre, this turns a steering column, which rotates the attached steering shaft and a worm equipment known as the pinion. This equipment sits on the ‘rack’, a length of metal with some teeth cut involved with it. In order the pinion rotates, the rack movements either left or right, based on your steering input.
Power steering provides a device to one side of the rack with a hydraulically actuated piston inside. A rotary valve directs hydraulic liquid to either the proper or left side of the piston – depending on the steering direction – which applies strain on the piston and reducing your time and effort had a need to move the rack.
The rack-and-pinion gearset does a couple of things:

It converts the rotational motion of the tyre into the linear motion needed to turn the wheels.
It offers a gear reduction, making it easier to turn the wheels.
On most cars, it takes three to four complete revolutions of the tyre to help make the wheels turn from lock to lock (from far left to far right).