Rack and pinion steering uses a gear-set to convert the circular motion of the steering wheel in to the linear motion necessary to turn the wheels. It also provides a gear reduction, so turning the tires is easier.
It functions by enclosing the rack and pinion gear-established in a metallic tube, with each end of the rack sticking out from the tube and connected to an axial rod. The pinion gear is mounted on the steering shaft to ensure that when the tyre 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 move from lock to lock (from far right to far remaining). The steering ratio demonstrates how far to carefully turn the steering wheel for the wheels to turn a certain quantity. A higher ratio means you should turn the tyre more to carefully turn the wheels a certain quantity and lower ratios give the steering a quicker response.
Some cars use variable ratio steering. This rack and pinion steering program uses a different number of tooth per cm (tooth pitch) in the centre than at the ends. The result is the steering is certainly more sensitive when it’s turned towards lock than when it’s near to its central position, making the automobile 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 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 steering wheel, 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 some teeth cut into it. In order the pinion rotates, the rack techniques either left or correct, based on your steering input.
Power steering adds a device to 1 part of the rack with a hydraulically actuated rack and pinion china piston inside. A rotary valve directs hydraulic fluid to either the right or left part of the piston – depending 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 two things:

It converts the rotational motion of the steering wheel in to the linear motion had a need to turn the wheels.
It provides a gear reduction, which makes it easier to turn the wheels.
On most cars, it takes 3 to 4 complete revolutions of the steering wheel to help make the wheels turn from lock to lock (from far remaining to far right).