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What Is An Axle On a Car?

What Is An Axle On a Car?

Axles are important components of any vehicle, but they are often overlooked. Axles are designed to connect and propel wheels while retaining the position of the pair of wheels it is connected to.

In cars, the engine applies force to the axle, which then rotates the wheels and causes the vehicle to move forward.

A car’s axle is a shaft or rod that rotates the wheels while supporting your vehicle’s weight. Axles are necessary components of all vehicles and are classified into three types: stub, rear, and front.

Are you interested in learning more about axles, such as how they work and why they are needed? If so, keep reading. Here you can find all the information you need about the axles on your vehicle.

The Car Axle Defined

Axles are steel rods connecting a pair of wheels. They use the car’s transmission’s torque (or rotational force) to move the wheels. The axle works as a bridge between two tires and uses power provided by the transmission to move the wheels forward, which makes the car move.

Since the entire purpose of cars is for them to move, the axles are “secret weapons” that keep your vehicle moving, even if you are unaware of their existence.

Number of Axles on a Car

You may wonder how many axles the typical vehicle has. The answer varies since different makes and models of vehicles have different numbers of axles.

At a minimum, cars will have two axles that work with the front and back wheels. For vehicles larger than traditional passenger cars, there are often more axles.

There is a simple way to determine how many axles a vehicle has. A generally accepted rule is cars and trucks have one axle for each pair of wheels.

As a result, they are often referred to as two-axle vehicles. These are most of the vehicles on the road today.

Different Car Axles

You will find there are different types of car axles, and each one serves a unique purpose. Axles on a car can be categorized by their position – in the front or rear– or by their function.

The main job of any axle is to hold the weight of the vehicle and transfer this to the wheels.

Modern trailers and horse-drawn trailers often have one or more dead axles. This means the axles do not rotate as the wheels move. Live axles (used for most modern vehicles) rotate and transfer power to the wheels.

Different Car Axles

This means there are the following:

  • Live axles: These are designed to keep the wheels moving.
  • Dead axles: These are designed to support the vehicle’s weight; however, they do not move the wheels.

Dead and live axles are categories based on the function of the part.

You can also classify axles based on their position on the vehicle. These include the following:

  • Front axle: Found in the front of a vehicle and can be dead or live. If the front axle is live, it will move the wheels and support the steering while managing shocks from potentially rough terrain.
  • Rear axle: Found at the vehicle’s rear and is usually live. It helps to move a vehicle forward. There are three rear axle options: a three-quarter floating axle, a full floating axle, and a semi-floating axle. Each type of rear axle serves a unique purpose.
  • Stub axle: Found in cars with rear-wheel drive and connected to the front axle using kingpins, which connect the sub and front axle.

There are a few types of stub axles, which include the following:

  • Lamoine: Features an L-shaped spindle and kingpin, which replace the yoke.
  • Lamoine reverse: Reversed arrangement of the Lamoine.
  • Elliot: Attached to the front axle using a cotter, kingpin, and yoke.
  • Reverse Elliot: Reversed arrangement of the Elliot stub axle.

As you can see, the axle arrangement for a vehicle is often more complex than you realize due to the different types and arrangements.

Factors That Determine the Type of Axle Your Car Has

Several factors determine the type of axle a vehicle requires. One factor is the amount of force produced.

Many modern vehicles have pre-designed axles that come in standard formats. Others have customized ones to fit the specifications and needs of the vehicle. Most customized axles work best for cars since they provide more control over the wheels. With these types of axles, the speed and torque can be adjusted to a much finer degree.

Signs of a Bad Axle

Now that you know what an axle is and how it works, it is time to learn more about how to tell if you have a bad axle. After all, this is an essential part of your vehicle and necessary to keep it moving. If your vehicle has a bad axle, it may result in issues down the road.

The good news is that some signs will let you know if you are dealing with a bad axle, which includes the following:

  • Your car does not move
  • You experience vibrations when you drive
  • Your car has begun leaking grease
  • You notice a clicking or clunking sound

You likely have a bad axle if you notice any of these issues. It is a good idea to have it inspected by a professional.

Selecting the Right Axle for a Pickup Truck

Did you know that not all pickup trucks have the same axle ratios? A standard truck axle ratio is 3.55:1, which means the drive shaft turns 3.55 times each time the wheel rotates one time.

For situations where you will not use your truck to haul large loads, the standard axle ratio is sufficient. However, choosing a higher axle ratio is recommended for hauling larger loads or towing heavy trailers. This will ensure that the axle can handle the additional weight.

What to Consider When Choosing Axles

If you are selecting an axle for your vehicle because the original one no longer operates, is broken, or because you want something more efficient, there are a few things to remember. These include the following.

When you see the window sticker on the vehicle, it will include fuel economy info. This is based on the standard axle ratio. For trucks with custom axle ratios, it is understood that the fuel economy is lower than what is posted.

Comparing the custom axle ratios from one automaker to another is impossible. Factors like unique tire sizes will affect the gear system and final figure.

Some dealers will refer to the lower axle ratio as the tall gears and higher axle ratios as short gears.

Key Takeaways About Your Vehicle’s Axles

As you can see, there is a lot to know about your vehicle’s axles. Understanding these and their role in making your vehicle move can help you see why they are so important.

If you have an issue with your axle and are unsure what to do, it is best to get to a mechanic for assistance.

If you found this article helpful, you may want to take a look at some of the related resources below as well!

Zach Reed

Hi, I'm the founder of! Having owned a wide variety of vehicles in my life, I was astounded at how hard it can be to find answers to common automotive questions. Rather than sit idly, I decided to create this website to help others!