Rack and pinion steering runs on the gear-arranged to convert the circular motion of the tyre into the linear motion required to turn the tires. It also offers a gear reduction, so turning the tires is easier.
It works by enclosing the rack and pinion gear-set in a metallic tube, with each end of the rack protruding from the tube and connected to an axial rod. The pinion equipment is mounted on the steering shaft to ensure that when the tyre is turned, the gear spins, shifting the rack. The axial rod at each end of the rack connects 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 remaining). The steering ratio demonstrates how far to carefully turn the tyre for the wheels to turn a certain quantity. An increased ratio means you should turn the steering wheel more to turn the wheels a particular quantity and lower ratios supply the steering a quicker response.
Some cars use adjustable ratio steering. This rack and pinion steering program uses a different number of teeth per cm (tooth pitch) in the centre 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 position, making the automobile more maneuverable.
There are two main types of rack and pinion steering systems:
End remove – the tie rods are attached to the end of the steering rack via the inner axial rods.
Centre remove – bolts attach the tie rods to the center of the steering rack.
As steering is vital for controlling your car, it’s vital that you diagnose and repair any steering issues as quickly as possible.
The chances are your vehicle has rack and pinion steering.
Thankfully, the basics aren’t hard to understand at all: it’s about turning rotational motion into linear. When you switch the tyre, this turns a steering column, which rotates the attached steering shaft and a worm equipment referred to as the pinion. This equipment sits on the ‘rack’, a length of metal with a series of teeth cut involved with it. So as the pinion rotates, the rack moves either left or correct, depending on your steering input.
Power steering provides a device to one part of the rack with a hydraulically 
actuated piston inside. A rotary valve directs hydraulic liquid to either the rack and pinion china proper or left part of the piston – depending on the steering path – which applies strain on the piston and reducing the effort had a need to move the rack.
The rack-and-pinion gearset does two things:
It converts the rotational movement of the steering wheel into the linear motion needed to turn the wheels.
It provides a gear reduction, making it easier to turn the wheels.
On many cars, it takes 3 to 4 complete revolutions of the tyre to help make the wheels turn from lock to lock (from far still left to far right).