Most of us care little about our cars. We just want it to run and drive the moment we press the ignition key. However, suppose you have ever wondered about the inner workings and operations of a car. In that case, you might have done your research and discovered axles. Well, how many axles does a car have?
Generally, a car has two axles, with each axle holding two wheels. Cars or smaller trucks, in general, have two axles. Larger vehicles, such as semis, may have more than two axles. Several types of axles help to perform more jobs than just driving the wheels.
This article discusses the number of axles a car has. We also look at axles and if a car must have axles. Lastly, we also examine if you have a bad axle and why axles break down.
What Are Axles?
Axles are central shafts connecting wheels to your car. Their main job is to take power from your engine and transfer it to the wheel, rotating it to move forward or backward; they are also part of the car that supports its weight, meaning it tends to be a thick and solid piece of metal.
Axles are probably one of the most major and crucial parts of any vehicle. They are essentially central shafts that connect the wheels. Axles usually transfer the power from the engine to the wheels, controlling the wheels to rotate forward or backward. Every vehicle is required to have axles to operate.
Axles are almost never connected directly to the wheels. In between the axles and the wheels, there are usually bearings and bushings to support it.
Axles are also expected to support the weight of the vehicles. As a result, they are usually solid, thick pieces of metal. On top of that, you may also see heavier vehicles using bigger and thicker axles since they have more weight.
How Many Axles Does A Car Have?
Generally, a car has two axles, a front axle and a back axle. The common rule is to assume that for every two wheels, you have one axle. Heavier vehicles may use more axles to bear more weight, and each axle may have more than one wheel.
A regular passenger car such as your Toyota Camry and many others commonly has two axles. You get one front axle and a back axle. These axles could be dead, live, semi or three-quarters floating, depending on the build specifications of your car maker.
The common rule you can apply to calculate axles is to look at the wheels. The axle numbers are usually half of the wheels you can count. For example, you may see four wheels on your Honda Civic. That means the car has two axles.
However, such a formula may not work with heavier vehicles. This is because heavier vehicles, such as semis, may have multiple wheels connected to an axle. A single axle may have flour wheels to support the immense weight these trucks are pulling.
When these vehicles, the best is to simply calculate the outside wheels and divide them by two to get the axle count.
What Are The Types Of Axles?
There are three types of axles, front axles, rear axles, and also stub axles. Each axle performs a different job and may also come with its own variations. For example, rear axles can be either semi-floating, three-quarters floating, or full floating. Modern cars tend to have a more complicated axle system.
Generally, there are three major types of axles – front, rear, and stub. Each of these types of axles also comes in its own variation. This is because as cars evolve, more and more specific requirements are required, meaning the axle system has to also evolve to cater to it.
Other factors that may influence the types of axles used may be the force produced on the vehicle. And also the gear mechanisms used in the vehicle.
|Types of Axles||Axle Variations|
|Front Axle||Live Front Axle
Dead Front Axle
|Rear Axle||Semi-Floating Rear Axle
Three-Quarters Rear Axle
Full Floating Rear Axle
|Stub Axle||Elliot Stub Axle
Reverse Elliot Stub Axle
Lamoine Stub Axle
Reverse Elliot Stub Axle
Front axles are, as it says, located at the front of the vehicle. Aside from supporting the car’s weight, it also helps with steering, as it works in sync with your steering wheel to turn the wheels left and right. Front axles also help in processing shocks from uneven road surfaces.
A front axle usually consists of a beam, swivel pin, track rock, and stub axle. Front axles are usually very sturdy. As a result, you tend to see them made from carbon or nickel steel.
You can further break down a front axle into several types:
Live Front Axle
The word live and dead basically refers to whether they deliver engine power to the wheels. In the case of the live front axle, it does. Today, you may see many modern and 4X4 vehicles carrying live front axles.
Dead Front Axle
Dead front axles generally do not deliver any power to the engine but only perform the job of bearing the weight of the vehicle and rotating the wheels.; these types of axles are quite rare these days. You may only see dead front axles on super heavy pickups. Such as Ford’s Super Duty trucks.
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The rear axle can be found at the back of your vehicle. They usually focus on delivering power and torque from the engine to the wheels. In many cases, rear axles are live, which means they rotate with the vehicle’s wheels.
The rear axle usually comes in two halves, commonly called half shafts. They are then connected by the differential, which explains the large bulge at the center of the rear axle.
You may see three types of rear axles:
You usually see semi-floating axles on cars, SUVs, and middle-size trucks, such as half-ton or lighter-duty pickups.
Semi-floating axle connects the wheel to the flange of the axle shaft. One bearing supports the axle shaft, while the other goes inside the axle casing. It tends to be larger to accommodate two bearing sets and also to produce the same amount of torque.
Full-floating axles are not joined directly to the wheels but float in place and stay in their position. This is achieved by using two sets of bearings.
Full-floating axles are usually used only to deliver engine power and not for steering. Many larger, heavier vehicles use full-floating axles, such as heavy-duty or mid-size trucks with high towing capacity. Many 4X4s also may use full-floating axles.
Three-Quarter Floating Axle
Three-quarter floating axles can be said to be more complex but more reliable than semi-floating axles. It is usually prized and appreciated for its good ability to maintain wheel alignment well. People also love them for their ability to handle side thrust and engine torque well.
Stub axles are usually attached to the vehicle’s front axles. They are then connected to the front axle using kingpins, with a hinged connection to the steering knuckle.
Suppose the stub axle is connected to a dead axle. In that case, the stub axles simply attach to the vehicle to distribute the weight. Cars with independent suspensions tend to use stub axles.
You may see four types of stub axle:
Elliot Stub Axle
This is the most common stub axle type. The Elliot stub axle looks like a yoke and then uses a kingpin, thrust washer, and a cotter pin to connect to the front axle.
Reverse Elliot Stub Axle
As the name suggests, it is built in the reverse of the standard Elliot stub axle.
Lamoine Stub Axle
Lamoine stub axle is built to have an L-shaped spindle instead of the yoke-type hinge seen in Elliot stub axles. It also requires the use of kingpins. You might see Lamoine stub axles on tractors.
Reverse Lamoine Stub Axle
Reverse Lamoine Stub Axle is built in the direct opposite layout of a standard Lamoine stub axle.
Do All Cars Have Axles?
All cars have axles and must have axles. This is because axles are needed for many functions, such as bearing the car’s weight and transferring the engine power to the wheels. Some axles are also used to steer the car, with the help of the steering wheel. Axles also help wheels to spin in unison.
In general, you may assume that all cars have axles and must have some axle system underneath them. This is because axles perform many major functions that help a car move.
Axles are one of the main structural parts of a car. It helps to bear the weight of the vehicle, which means axles also help keep the car’s structural integrity. As a result, axles tend to be solid, thick pieces of hardened carbon steel.
Front axles also are required to work together with the suspension systems to absorb any impact from the surface. When a vehicle is driven on an uneven road, the shocks are partly absorbed and dealt with by the axles, spring coils, and shock absorbers.
Transferring Engine Power To Wheels
Perhaps an axle’s major role it helps to transfer the power from your engine to the wheels. Without axles, your engine will rev, but the wheels will not turn. There are intricacies in how transferring works, but the main point is axles help to rotate your car wheels.
Steering The Car
Axles are also used to help steer the car. Axles are usually connected to the steering column, meaning the axle turns the wheels when you move your steering wheel. Depending on the vehicle’s setup, the steering job could be done by either the front axle (front wheel drive) or the back axle (back wheel drive).
Can Axles Break Down?
Axles can break down due to the immense hard work it does for your car. You are likely to have broken axles if you consistently overload your vehicle or drive an old car with rusty axles. If you drive your car frequently through uneven terrain, your axle may break too.
In general, axles are not the parts of your car that frequently break down. This is because it is usually built to be sturdy enough to handle the immense weight, pressure, and shocks the road can bring.
However, in some situations, axles can break down by malfunctioning or completely breaking into two. Abuse and age are the most common reason for axles to break down:
Axles can break down if you consistently overload your vehicle with excess weight. Commercial trucks are known for doing this, and the excessive weight was eventually passed down to the axles.
When you combine the extra weight with the shocks delivered from the road when the trucks are being driven, the force may be too much, breaking the axle in two.
This is more common with 4X4 vehicles, which may be on an Overlanding trip. Very uneven terrain could place a lot of stress and force on the axles, which have to move to accommodate the extreme positioning of the wheels.
You may also see people driving their cars through uneven terrain at high speed, seemingly unconcerned about how the impact may stress their axles. These actions eventually may result in the axles being broken or bent beyond use.
Old, Rusty Axles
As much as axles are made of carbon or hardened steel, they are still susceptible to age and rust, the sworn enemies of metals. If you own an old vehicle and notice some rust on the axle, consider taking out the axles and inspecting how extensive the rust damage is.
This is because if the rusting is too extensive, you risk breaking your axles in two while driving, which is highly dangerous if you are on the road. Consider replacing the rusty axles for peace of mind.
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How Do You Know If Your Axle Is Bad?
Problematic or broken axles leave a very clear sign on your car. Your car’s wheels may not move when you press on the accelerator. You may also hear clunking when you put your car into gear. You may also feel a lot of vibrations when driving. Your vehicle may also drive oddly or look uneven in height when parked.
Unlike other parts of cars, a broken or problematic car axle usually leaves you with a clear sign that something is off. This is because axles perform such important work for your car that if they break down, you will notice it immediately.
Some of these signs could also mean breakdowns on other vehicle parts. However, it may also be caused by your axle. As such, when inspecting these breakdowns, also take a look at the axles to ensure that it works well.
If you put down your gears and hear a loud clunk, there is something wrong with your axle. This is because axles are the main structure that transfers your engine’s power to the wheels, and gears help connect your engine to your axles.
If a clunking sound appears when you connect your engine to your axle, chances are there may be something wrong with your axles.
Axles are responsible for helping handle some of the shocks and vibrations that may come from the wheels as you drive through uneven terrain. If you detect excessive vibrations in your car, there may be issues with your axle.
However, vibrations in your car can also mean other less major issues, such as engine mounting, coil springs, or shock absorbers. This means you want to inspect these things before deducing that your axle is broken.
If you put down your gears, step on the gas pedal, and the wheels do not move, you may have issues with your axle.
This is because the axle connects the engine power to the wheels. If the engine is revving well and the gears are engaged, your axle should deliver the power to your wheels.
If you notice that your car steering is giving you weird feedback, consider getting your axles checked. This is because axles are commonly connected to the steering column to steering your car.
If you notice excessive vibration on your steering wheel or odd feedback, such as the steering wheel becomes harder to turn, it could be your axles. However, also inspect your steering system to ensure all is good on that side.
If you notice any leaks from your axles during your routine vehicle service, consider inspecting the issue further. This is because leaks can be something as small as a hardened gasket that needs changing or major structural damage inside the axles.
Observe places such as the brake seal on a driveshaft. Aside from that, also inspect the CV joints of the axles for signs of leaking. These are the most common failure points that cause leakages on the axles.