Rack and pinion steering uses a gear-established to convert the circular movement of the tyre into the linear motion necessary to turn the tires. It also provides a gear reduction, therefore turning the tires is easier.
It works by enclosing the rack and pinion gear-arranged in a metallic tube, with each end of the rack protruding from the tube and connected to an axial rod. The pinion gear is attached to the steering shaft to ensure that when the steering wheel is turned, the gear spins, moving the rack. The axial rod at each end of the rack connects to the tie rod end, which is attached to 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 turn the tyre for the tires to turn a certain quantity. An increased ratio means you have to turn the steering wheel more to turn the wheels a specific quantity and lower ratios supply the steering a quicker response.
Some cars use variable ratio steering. This rack and pinion steering system uses a different number of tooth per cm (tooth pitch) in the centre than at the ends. The result is the steering can be more sensitive when it’s turned towards lock than when it is near 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 end of the steering rack via the inner axial rods.
Centre take off – bolts attach the tie rods to the centre of the steering rack.
As steering is essential for controlling your vehicle, it’s vital that you diagnose and repair any steering issues as quickly as possible.
The chances are your car has rack and pinion steering.
Thankfully, the fundamentals aren’t hard to grasp at all: it’s about turning rotational motion into linear. When you convert the steering wheel, this turns a steering column, which rotates the attached steering shaft and a worm gear referred to as the pinion. This equipment sits on the ‘rack’, a amount of metal with some teeth cut involved with it. In order the pinion rotates, the rack techniques either left or right, based on your steering input.
Power steering adds a device to one part of the rack with a hydraulically actuated piston inside. A rotary valve directs hydraulic liquid to either the proper or left aspect of the piston – based on the steering direction – which applies pressure on the piston and reducing the 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 in to the linear motion needed to turn the wheels.
It offers a gear reduction, making it simpler to turn the wheels.
On most cars, it takes three to four complete revolutions of the steering wheel to make the wheels turn from lock to lock (from far remaining to far right).