Rack and pinion rack and pinion china steering uses a gear-set to convert the circular movement of the steering wheel 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-established 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 so that when the steering wheel is turned, the gear spins, moving the rack. The axial rod at each end of the rack links to the tie rod end, which is attached to the spindle.
Most cars need 3 to 4 complete turns of the tyre to move from lock to lock (from far to far left). The steering ratio shows you how far to carefully turn the tyre for the tires to turn a certain quantity. An increased ratio means you should turn the steering wheel more to carefully turn the wheels a specific amount and lower ratios supply the steering a quicker response.
Some cars use adjustable ratio steering. This rack and pinion steering system uses a different number of tooth per cm (tooth pitch) at the heart than at the ends. The result is the steering is more sensitive when it is switched towards lock than when it is close to its central position, making the car more maneuverable.
There are two main types of rack and pinion steering systems:
End take off – the tie rods are attached to 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 vital for controlling your vehicle, it’s important to diagnose and restoration 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 change the tyre, this turns a steering column, which rotates the attached steering shaft and a worm equipment referred to as the pinion. This gear sits on the ‘rack’, a length of metal with a series of teeth cut into it. So as the pinion rotates, the rack moves either left or correct, based on your steering input.
Power steering adds a device to one aspect of the rack with a hydraulically actuated piston inside. A rotary valve directs hydraulic liquid to either the right or left part of the piston – based on the steering direction – which applies pressure on the piston and reducing the effort needed to move the rack.
The rack-and-pinion gearset does a couple of things:
It converts the rotational motion of the steering wheel in to the linear motion had a need to turn the wheels.
It offers a gear reduction, making it simpler to turn the wheels.
On many cars, it takes 3 to 4 complete revolutions of the steering wheel to make the wheels turn from lock to lock (from far still left to far right).