Keep Learning.
Keep Growing.

How Car Steering System Works – in Simple English

A car's steering wheel is connected to the housing of a steering rack.
A typical car steering system.

Personally, I’m very scared of ghost. The only thing scarier than Chucky, the killer doll is…

Driving without a functional car steering system.

Without it, you can’t tell your car to move to the left or right.

Scary, right?

Car steering system consists of (i) steering wheel, (ii) steering column, and (iii) steering rack.

They make changing your car’s direction possible by converting rotational motion of your steering wheel into a lateral movement on your car wheels.

The steering system also reduces the steering effort to turn the car with the use of gear reduction.

In this article, we will be looking at each component that makes up our car steering system. Feel free to jump to any section below to find out more about a particular part.

Basic Steering Components

An (over) simplified diagram of a traditional car steering system. Steering wheel is labelled as number 1, steering column as number 2 and steering rack as number 3.
An (over) simplified diagram of a traditional car steering system. Image courtesy of LaurensvanLieshout.

Most, if not all of the car steering system will have 3 main components: Steering Wheel, Steering Column, Steering Rack.

The components are related to each other like this.

Driver holds the steering wheel.

Steering wheel is connected to a steering column.

Steering column is connected to a steering rack.

Finally, the steering rack connects to the knuckle on our car wheels.

That is the entirety of a car steering system.

Now, let’s see break it down one by one and find out what they do.

Steering Wheels

"<yoastmark

Let’s start with something we are all familiar with – the steering wheel.

It is the circular part of the car that we holds when driving. If you’re not doing that, you probably should!

You will find your car horns, turn signals and window wiper switch here.

We are also beginning to see more functions added here in modern vehicles, designed to keep driver’s hands on the wheels. These includes audio system, cruise control and many others.

The steering wheel is responsible for taking the driver’s input, while the rest of the steering system responds accordingly to this input to change the car’s trajectory.

The steering wheel hub mounts directly onto the steering column.

Fun fact of the day – The larger the steering wheels, the easier it is for you to turn your car.

This is because…

Torque = Force * Distance

Or in another words,

Turning Power = Driver’s Steering Effort * Diameter of Steering Wheel.

Yes, while that is true. Our steering wheels have actually become smaller over the years.

This is because of the introduction of power assisted steering rack. It allows us to use a smaller steering wheels while still keeping it easy to turn.

Less space taken up by steering wheel gives more flexibility to the car manufacturer to design and optimize for comfort and safety.

Steering Column

Ever wondered how your directional signals flicks back to the original position after you turn?

Well, your answer lies within the steering column.

Steering column is the middle man that transfer steering effort from the steering wheel to the steering rack. They also houses the electrical wiring and mechanisms of your switches.

There are two parts to a steering column assembly, namely (i) steering column housing and (ii) intermediate shaft.

If you’d like to know steering column from the inside-out (quite literally), Speedkar made a really great Youtube video disassembling a steering column and explaining how a steering column work.

It’s worth a watch.

Steering Column Housing

Steering column housing is the upper portion of your steering column. It contains the internal wiring and inner mechanisms of your steering wheel switches. These includes:-

  • Airbag module
  • Multi-function switch
  • Window wiper switch
  • Ignition switch
  • Car headlight
  • Turn signal
  • Car horn

Steering column is one of the most overlooked part of our car steering system because it typically requires little to no maintenance.

Intermediate Shaft

Intermediate shaft is located right below the steering column.
Intermediate shaft (a.k.a steering shaft) is located right below the steering column.

Just below the steering column housing, we have the intermediate shaft.

This intermediate shaft and steering wheels are connected together.

When you turn the steering wheel, the intermediate shaft will turn accordingly too.

So there you go!

The purpose of a intermediate shaft is to accept the rotational motion of the steering wheel and then pass it forward to the steering rack located below it – which we will discuss later.

I know what you are thinking – “So why do we have such a complicated looking mechanism here? With all the universal joints and whatnot? Why not just use a simple, straight shaft?”

Yes, a simple straight shaft is good enough to transfer the rotational motion.

But…

It would be so awkward to drive with!

Universal joints are there to let the steering wheel incline at an angle that is comfortable for the driver.

The picture below should speak for itself.

The picture on the left shows a steering wheel angled in a comfortable - upright position while the image on the right is a uncomfortable, horizontally placed steering wheel on a tractor.
The use of universal joints allow steering wheel to be angled better (left image) for a more comfortable drive. Image courtesy of Øyvind Holmstad.

You know what is so brilliant about this car part?

It is not just good for comfort, but the intermediate shaft can saves lives too.

Invented by Bela Barenyi, the intermediate shaft has a collapsible mechanisms that collapses during heavy frontal impact.

It prevents the intermediate shaft from impaling through the steering wheel and (possibly) the driver’s head like a spear.

The collapsible design features an inner and outer sleeve.

Outer sleeve is bigger and hollow.

Inner sleeve is smaller so that they can fit inside the outer sleeve.

Steel bearings is placed between them to maintain contact between the two sleeves.

Finally, a special kind of resins glues the steel bearings to the sleeves.

Here comes the important part!

When a specific level of pressure is exceeded during frontal collision, the special resins shatters while absorbing the impact.

Without the resin holding the bearings in place, the inner sleeve falls down the bigger hollow sleeve.

Just like a telescope!

This feature is literally a life-saver.

Based on statistics from National Highway Traffic Safety Administration, collapsible steering column helps to prevent 1,300 fatalities and 23,000 non-fatal injuries on an annual basis.

Engineers are pretty awesome, aren’t they?

Steering Rack

This is an electric power assisted steering rack. You can see that the electric motor is attached to it at the bottom.
This is an electric power assisted steering rack with the electric motor attached to it.

Steering rack is essentially an enclosed metal casing with rack and pinion gears inside of it. It is connected to the bottom part of intermediate shaft.

The main reason why we need steering rack is to:

    • Helps to convert rotational motion to lateral motion
  • Makes steering easier through gear reduction

Okay, so a quick recap.

When the driver turns, the rotational motion gets transferred from the steering wheel, through the steering column, then the intermediate shaft, and finally arrives at the pinion gear of your steering rack.

Steering rack is where the rotational motion of the steering wheel gets converted to a lateral motion (left or right movement).

How? Through its rack and pinion gears.

The pinion gear mesh with a straight row of teeth, known as the rack gear.

The steering shaft connects to the pinion gear of your steering rack. This pinion gear meshes with the rack gear to convert rotational motion into a lateral motion on your car wheels.
This is a simplified diagram of a tradition rack and pinion steering rack system. Image courtesy of PaulsGiganticGarage.

When the driver turns, the pinion gear forces the rack gear to move side to side.

As the both ends of the rack gear is connected to the car wheels, the car wheels will move side to side as well.

That’s exactly how cars changes direction when we turn our steering wheel.

But…

Steering a 1,000 kg car is just not going to be easy, especially if you car is stationary. So as usual, the engineers try to make things more convenient and better.

They came up with what we call… power assisted steering rack, or power steering in short.

Power steering rack works the same way as how a non-power assisted, rack and pinion steering rack would, but with added components.

These could be either an engine-driven pump (hydraulic power steering) or computer-controlled electric motor (electric power steering).

They provide the additional power to help you turn the car.

Regular Steering:

Car Steering = Driver’s Steering Effort + Gear Reduction

Power Steering:

Car Steering = Driver’s Steering Effort + Gear Reduction + Additional Support (Hydraulic / Electric)

If you’re wondering how they work, that would be a whole new chapter of story and we won’t be discussing it today.

But, we’ll be writing an article about that soon, so stay tuned!

Conclusion

If you’re still reading this, amazing. We’ve reached the finish line.

You now know how a car steering system works!

A car steering system is basically just steering wheel, steering column and steering rack.

They work together in harmony to make turning your car possible and comfortable.

Car steering systems are usually very robust. In another word, they are built to last.

But if you do have any problem with your car steering system, it will most likely be your steering rack system acting up (really, trust us).

If you would like to know for sure, we have written an article about the Top 7 steering rack problems you can identify [with Videos!]. Give it a read, it can potentially save you thousands of Ringgit Malaysia.

Or, you could just get a free test drive from one of our colleagues. We will be more than happy to help.

Until then, drive safe and drive smart!

Leave a Reply

We thought you'd love these topics too!

Electric power steering uses electric components to make steering easier.

What is Electric Power Steering Rack and How it Works?

Electric power steering rack is a type of power assisted steering rack that uses electric current and electronics to make it easier for us to steer our car. With virtually

Read More »
Turbocharger gives you wings!

Turbocharger: What is it and How it Works?

“Vroom vroom vroom – stutututuutuuu” says the Turbocharger. If you’ve seen or heard a car passing by you with blazing speed, loud buzzing noise and fumes coming out of their

Read More »
Coil-over shock absorbers looks very similar to a strut. They have a mounted spring on the upper portion of the shock absorber.

Shock Absorber: What is it and How it Works?

Shock absorber makes our ride comfortable by dampening the car vibrations we get from uneven road. But, here’s a fact. Roads are never perfectly smooth. (I guess Malaysians would know

Read More »

Follow Us

Close Menu
×
×

Basket

%d bloggers like this: