How Many Axles Does a Car Have and What Are the Types?

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“How many axles does a car have?” is asked by many car enthusiasts since the number and definition of axles appear to be confusing. Fortunately, we’ve done the research and in this article, we’ll discuss the number of axles that are under cars and consider the various types.

Also, we’ll define what an axle is, its functions, its replacement costs and everything you’ll need to know. In the end, we’ll answer the most common questions on axles, so keep reading!

How Many Axles Does the Usual Vehicle Have?

The usual vehicle has two axles; one in the front and the other at the rear of the vehicle. Their primary duty is to connect both sets of wheels and enhance the car’s forward or backward movement. However, other types of cars have more than two axles.

Vehicles with extra sets of wheels, aside from the usual two sets, such as trailers have extra axles. These axles not only move the cars but help to support the weight and length of the vehicle. This is why car axles are made of strong materials such as steel to support the weight of the car and the extra load that’ll be heaped on them.

However, if the load is too much, there would be an axle break that might need replacement or repair depending on the extent of the damage.

– All About Axles

You might be asking “So what is an axle on a car?” An axle is defined as a shaft that links two wheels on opposite sides of a vehicle together. Some axles use rotational force to move the wheels while other axles allow the wheels to rotate around them. Also, they hold each wheel in place, preventing them from rolling away.

The axles form an integral part of the drivetrain that moves your vehicle without which vehicles would be unable to move. There are live or driving axles that move the vehicle forward by utilizing the torque from the engine and there are dead or non-driving axles that are driven by the driving axles. Thus, in a front-wheel drive (FWD) the driving axles are in the front while the dead axles are at the rear while a rear-wheel drive (RWD) has its driving axles in the rear.

Four-wheel drives and some modern FWDs use constant velocity, also known as cv axles, which we’ll explain later in this article. The non-driving axles only link their respective wheels and hold them in place while being driven or pushed. The axles are all connected to differentials that enable cars to negotiate turns and curves smoothly.

– The Various Types of Axles

There are three axle types which are front, rear and stub axles. The front axle connects the two front wheels and transfers power from the engine to the front wheels for movement. However, if the vehicle is rear-wheel drive, then the front axles would be considered dead because they are not directly receiving power from the engine. The front axles are made up of four parts including rod, track, beam, swivel pin and stub axle.

Like in the front axle, the axle in the rear is rather connected to the engine and directly receives power to move the vehicle. It is also connected to a differential which enables the wheels to turn at different speeds, especially when negotiating a curve. This helps the tires to have a better balance and traction on the road. In most rear-wheel drives with limited speed differentials, one of the wheels is live while the others turn when the need arises.

There is also the fixed rear differential where both wheels turn at the same time and speed. Types of rear axles include semi-floating, full-floating and three-quarter floating. Then there are the stub axles, also known as stud axles, which are short axles that are attached to one front wheel and are different from the regular axles that connect two wheels. These axles come in four different types which are the Eliot, Reverse Elliot, Lamoine and Reverse Lamoine.

– The Rear Axle Types

As we’ve already discovered, there are three axle types, namely semi-floating, full-floating and three-quarter axles. The semi-floating rear axle shaft handles both the rotational force and the weight of the vehicle and is used in SUVs, pickup trucks and midsize vehicles.

The full floating type has the weight of the vehicle resting on the axle housing, thus the axle shaft only provides rotational force to move the wheels. The third type of rear axle is the three-quarter floating axle, which combines the features of the semi-floating and full-floating rear axles.

The full-floating axles are made of strong materials that can withstand the toughest conditions and are used in carrying extremely heavy loads. Semi-floating rear axles are less strong but deliver excellent performance and driving capabilities compared to their floating cousins.

Three-quarter axles are more complex but are stronger than their semi-floating counterparts and can deliver excellent performance as well, though not at the level of semi-floating axles. They also partially support the weight of a vehicle.

– The Different Kinds of Stud Axles

The Elliot is connected to the front wheel via a kingpin, a yoke and a cotter while the Reverse Eliot uses the opposite arrangement of the Elliot. The Lamoine uses an L-shaped spindle while the Reverse Lamoine is the opposite of the Lamoine.

– Constant Velocity Joint Axle

Constant velocity joint axles are devices that connect a car’s transmission to its wheels and allow the vehicle to move smoothly, even on rough surfaces. The constant velocity joints work by transferring power to wheels and they help a vehicle to turn even when accelerating.

The constant velocity joints also allow the car’s suspension to move smoothly and help the driver to maintain total control over the vehicle. They are usually found on the car’s drive axles and come in two kinds – ball joints and tripod joints. The ball joints are the ones near the wheels on the outer joint while the tripod joints are the ones on the inner joint. In all, the joints are four and are protected by flexible plastic covers.

However, due to the nature of their work, especially on bumpy roads, the constant velocity joints are frequently subjected to wear and tear. The rubber part of the joints is made with durable materials that can last for many miles but they can tear and leak grease. The tears can also allow dirt to sneak into the joints, which can wear them down more quickly.

How Do You Know Your Car’s Axles Need Replacement?

You will know your car’s axles need a replacement when you notice symptoms including tires’ refusal to rotate, car straining, wobbling wheels and clunking noises. Others include brake pad misalignment and leaking of oil from the driveshaft onto the insides of the car’s wheel.

The car axle replacement cost will depend on the type of car. Smaller cars usually cost between $100 and $150 each while bigger vehicles may cost between $300 and $1,500 for each axle.

– Wheels Refuse to Rotate

One of the surest ways to know that your car’s axles are bad is when the wheels don’t rotate when you press down the accelerator pad while the gears are engaged and the car is running. Since the axles are responsible for the movement of the car, it should make sense that they should be checked when the car refuses to move.

– Car Strains When Accelerator Is Pressed Down

This time the car moves but its movement doesn’t correspond with how far down you’ve pressed the accelerator paddle. If the car moves slowly no matter the pressure you put on the accelerator paddle, then it’s time to have the axles checked.

– Clunking Noises from Under the Car

When you hear clunking noises coming from under your vehicle whenever you press down the accelerator, then it is the axle that may have developed a fault. This noise is usually observed when a car is negotiating a curve.

– Wobbling Wheels

Another sign that indicates bad axles are wobbling wheels when the vehicle is in motion. Since the axles hold the tires firmly in place, they are the prime suspects whenever the tires are unstable. Wobbling tires can either be caused by a broken axle or a loose fastener. If the axle is broken, then it needs to be replaced, which can cost between $120 – $180.

– Misalignment of Brake Pad

This happens when your brake pads do not properly align with the wheels and rotors during braking. A misaligned brake pad can cause the vehicle to slip or skid to a stop.

– A Leaking Driveshaft

Once you notice oil dripping from the driveshaft into the car wheel, then the axles may be going bad. This occurs when the brake seal on the car’s driveshaft is broken, leaking onto the brake drum.

Frequently Asked Question

– How Many Axles Does a Truck Have in Total?

A truck has two or more axles in total, depending on its length and its function. These axles support the weight of the vehicle while keeping the wheels in place. Many semi-trucks feature five axles and some trucks have six axles all helping to move the vehicle.

Conclusion

As promised, we’ve answered the number of axles cars have and the type of axles available. Here is a recap of all the most important points that this article has touched on:

  • Most cars have two axles that connect the front and rear wheels of the vehicles, while others have more than two axles depending on the sets of wheels.
  • In front-wheel drive, the axles in front receive power from the engine to move the vehicle while in rear-wheel drive, the rear wheels are responsible for vehicular movement.
  • The axle that directly receives power from the engine to move the vehicle is called the live axle while the other axle which is driven is known as a dead axle.
  • There are types of axles; the front, rear and stub and they all have their sub-types as well.
  • When you hear some clunking noises or the wheels refuse to turn when the engine is on and the gears engage, then you should know that the axle may be damaged.

Fixing an axle can be expensive, therefore, you have to take care of it by not overloading your vehicle. Also, when you notice signs of axle damage, repair them as quickly as you can to prevent future road accidents.

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