The drive shaft may look like a simple component of a vehicle, but the reality is that it’s a very complex component with parts such as CV joints and CV axles that provide intricate operations.
Understanding these subcomponents and their complicated operations will not only make you a better mechanic or motorist but also enable you to diagnose and repair any faults in the driveshaft system more effectively.
Now, a lot of people get confused when it comes to CV joints VS CV axles, not knowing the difference between these two critical driveshaft components. It begs the question: what’s the difference between them anyway?
To answer that, let me first explain that CV as used in the two driveshaft engineering terms above represents an acronym. To be precise, the acronym stands for “Constant Velocity”. Therefore, “CV Joints” and “CV Axles” are simply “Constant Velocity joints” and “Constant Velocity Axles” in full, respectively.
A CV axle is a central shaft for a rotating wheel fixed to the wheel, using a constant velocity joint among other things. On the other hand, a CV joint is just a joint used to connect the parts of the CV axle together.
In other words, a CV joint is just a component of a CV axle system that enables torque to transmit to the vehicle’s wheels through varying angles, supporting steering actions.
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Differences Between CV Joints and CV Axles In Depth
CV joints are components of the CV axle system. After all, a vehicle’s axle system is made up of two different types of joints; inner joints and outer joints.
On the other hand, the axle system is part of the drive shaft, which functions to transfer the engine torque from the differential or gearbox to the wheels. Different types of cars have different numbers of CV axles in their driveshaft system, ranging from two to four.
For example, front-wheel drive(FWD) cars have two CV axles. Note that these axles are only found in the front wheels since these are front-wheel drive vehicles.
Meanwhile, rear-wheel drive(RWD) vehicles with independent rear suspension have two CV axles. The axles are found in the rear wheels as these are rear-wheel drive vehicles. Also, we have all-wheel drive vehicles.
These are vehicles whose four wheels are equally powered by the engine. As such, they have four CV Axles, one axle per wheel.
A CV joint and a CV axle are both made of different materials, thanks to the differing composition of each. For example, a CV joint is made up of a cage, balls, and an inner raceway encased in a rubber boot housing, all of which are filled with lubricating grease.
The cage, balls, and the inner raceway are all made of steel, whereas the rubber boot housing is constructed out of rubber. It’s, therefore, safe to say that a CV joint is built out of two different materials; steel and rubber.
On the other hand, a CV axle is made purely of one material; SAE grade 41xx steel, which is also known as “chrome-molybdenum steel” or “chrome-moly steel.”
Apart from chrome-moly steel, this part can also be built out of SAE grade 10xx steel, also known as “carbon steel.”
CV joints typically last longer than CV axles. For example, they can last 70,000-130,000 miles before needing replacement. CV axles, on the other hand, typically can’t serve beyond 100,000 miles, before wearing out.
Similarities Between CV Joints and CV Axles in depth
- CV joints and CV axles both come in different sizes suitable for different types of vehicles.
- CV joints and CV axles are both available in standard and customized varieties that fit the specifications and needs of any particular vehicle. Matter of fact, the latter tend to work best for vehicles as they allow for more personalized control over the wheels.
- Different types of CV joints and CV axles exist. For joints, the two most commonly used types are the ball-type and the tripod-type. Ball-type CV joints are used on the outer side of the drive shafts(outer CV joints), whereas tripod-type CV joints are mostly used on the inner side (inner CV joints).
For CV axles, on the other hand, we have two different types of axles; front axles and rear axles. Located in the front wheels, the front axles have four main parts; the beam, the swivel pin, the track rod, and the stub axle.
Since front axles must be as strong as possible, they are made from sturdy materials such as nickel steel or carbon steel. Meanwhile, rear axles located in the rear wheels come in two halves(half shafts) connected by the differential. In most cases, they rotate with the wheels.
Final Thoughts
CV joints and CV axles are important parts of a vehicle’s driveshaft system. A lot of people don’t know much about cv joints vs cv axles yet there are many significant differences between the two.
The main difference, however, is that a CV joint is a component of a CV axle system that enables torque to transmit to the vehicle’s wheels through varying angles, supporting steering actions.
