What is a Drivetrain? – Everything You Need to Know (and the Key Components Explained)
The drivetrain is among the least understood parts of a vehicle. But it’s crucial to understand its functions if you want to get the most out of your car or truck.
Many people, including most casual drivers, don’t know what a drivetrain is. They wouldn’t be able to tell you what it does or what parts it contains. Some may even mistake it for other systems that sound similar, like the driveline or the powertrain.
At the core, however, the drivetrain is a key component on any vehicle. It’s one of the most complex systems found in cars and trucks.
Have you ever wondered, “What is a drivetrain?” We’ll explain all about it and its parts in this article.
What Is a Drivetrain?
What does drivetrain mean? What is a drivetrain?
The quick answer is that the drivetrain works together with the engine and the gearbox to rotate your car or truck’s wheels. It’s located in the engine and produces the power that your vehicle needs to run.
Attached to the engine, you’ll find the transmission or gearbox. Its job is to keep the engine and the wheels in sync. The drivetrain connects to the transmission on one side and the wheels on the other.
What are the drivetrain components? The major drivetrain parts include the driveshaft, the differential, the U joint, the CV joints, and the axle shafts.
You’d have to get under the vehicle to see all the parts of the system. That’s why a lot of drivers and non-drivers don’t know much about them.
As explained, the drivetrain is responsible for transmitting the torque from the gearbox to the wheels.
How does it work then? The driveshaft receives the power from the transmission and sends it to the U-joint, which sends the power onto the differential.
The power then goes to the axle shafts. And from there to the wheel axles. Finally, the wheel axles send the power to the wheels.
The Key Components of a Drivetrain
Now that we’ve answered the “What is a car drivetrain” question, let’s move on to the individual parts.
Driveshaft
The driveshaft is the first major component of the drivetrain. As such, it’s the closest to the gearbox.
On most vehicles, the driveshaft is a long tube, usually made of steel. You can see it stretching down the middle of the vehicle, from the front to the back.
Its main function is to receive the power from the transmission and send it towards the wheels. It’s the longest part of the drivetrain system. Because of that, it needs to be robust enough to take a lot of punishment.
Differential
Making turns would be almost impossible without a differential. Why? Because it’s the part of the drivetrain that makes it possible for the wheels to turn at different speeds.
The differential is a gear train. It has three shafts that split the engine’s power and send that power to the wheels. The train also holds oil for lubricating the gear.
That’s why the differential oil level is one of the things you need to check on a vehicle. If the oil level drops too low, you might run into problems. Typically the recommended oil change is every 50,000 to 80,000 kilometres.
U Joint
The U-joint, or the universal joint, gives the driveshaft flexibility.
Without it, the shaft wouldn’t be able to move much. But with it, the driveshaft can change angles without sustaining damage or breaking. That makes the U-joint an essential part of the drivetrain.
CV Joints
The CV joints, not available on some rear-wheel drive vehicles, transfer power to the wheels at a variable angle and constant rotational speed. This allows the wheels to go up and down when you hit a pothole or anything uneven.
They need to be greased to work correctly, and dry CV joints can cause a lot of trouble for drivers.
Axle Shafts
The axle shafts come out of the differential, one on each side. They receive power from the final drive assembly and forward it to the wheels.
It’s important to note that the axle shafts only deliver power to the drive wheels. So, if your car is a front-wheel drive, only the front wheels receive power.
The Signs That Something Is Wrong with Your Drivetrain
Drivetrain malfunctions can affect other parts on your vehicle. If neglected, they can create severe road hazards. You wouldn’t want to ignore any symptoms of drivetrain problems.
So what should you pay attention to?
If you notice oil puddles under your vehicle, it’s always a red flag. Go to your mechanic and have the drivetrain checked out as soon as possible. Your differential might be leaking oil. If so, it’s not going to be black like used engine oil.
Another thing to watch out for is the appearance and smell of the transmission fluid. If it looks muddy or smells burnt, you should visit your repair shop.
Your gearbox should be smooth and silent. Any vibrations or strange noises when you shift gears might indicate something is wrong with the drivetrain.
You might hear whining and grinding noises coming from below the vehicle floor. These are clear signals that your drivetrain needs attention. If you notice these kinds of noises, go to your mechanic as soon as possible.
If you have problems turning, it might be due to a faulty drivetrain. The differential might be struggling. Or it could be the CV joints, or both.
That said, prevention is the best medicine. To prevent drivetrain malfunction, drive moderately rather than aggressively.
Keep an Eye on the Drivetrain
The drivetrain is one of the least understood parts of a road vehicle. It’s responsible for transmitting the engine’s power or torque to the wheels. Its main components include the driveshaft, differential, U-joint, CV joints, and axle shafts. Each of the components has to be in good condition for the system to work properly.
So, make sure to keep an eye out for the abovementioned symptoms. If you notice any, have the vehicle inspected as soon as possible. Neglected drivetrain problems can cause other issues and can also be very dangerous.
Your mechanic may be able to repair a malfunctioning drivetrain. However, it may need to be replaced altogether. If you ever need a new drivetrain, take a look at our selection.