An efficient driveline pays incredible dividends. But an inefficient one will cost you. Researchers at the Lawrence Berkeley National Laboratory discovered that optimizing the driveline of heavy-duty vehicles—without any other enhancement—improved HDV's fuel efficiency by 15%. On average, drivers used 86 fewer gallons of fuel every 10,000 miles!
Moreover, the study cited EPA reports that reveal driveline friction-reduction interventions reduce fuel consumption by 2%, regardless of a vehicle's size.
But, what is a driveline, exactly? Given its incredible impact, we believe the driveline is worth understanding in-depth. After all, at Point Spring & Driveshaft Co., providing high-quality driveline components for HDVs is our specialty!
Today, we invite you to discover everything you ever wanted to know about your auto's driveline.
What is a Driveline?
The driveline is a complex invention, but we can start with a concise definition.
A driveline system is a multi-component part of a car or truck that receives energy from the engine and transmission. Then, it uses and directs that energy to move in the right direction.
To get a better picture of the driveline's function, let's zoom out.
The Driveline Functions Within The Powertrain
The powertrain is the set of interdependent, internal machinery that makes a ground vehicle move. The vehicle’s powertrain encompasses:
● the engine
● the transmission
● the driveline
Energy moves through a powertrain from the engine to the wheels.
Energy Flows From Engine, Transformed and Regulated By Transmission
First, diesel and gasoline engines use internal combustion to transform the chemical energy within fuel into mechanical energy.
Then, the vehicle’s transmission uses a precise arrangement of gears to transform the engine’s output into rotational energy. It also regulates how much of this power it transmits to the driveline.
Driveline Receives Energy And Directs It To Wheels
The driveline, in turn, transforms the transmission’s rotational energy output into the kinetic energy, which propels the vehicle. Moreover, the driveline directs the kinetic energy, ultimately moving the wheels in the right direction.
The wheels are the final part to receive (and use) the energy. They're also the final component of the driveline.
Note: Driveline Vs. Drivetrain
Before we explore driveline components altogether, note that the terms “driveline” and “drivetrain” are synonyms in certain regions.
However, at Point Spring & Driveshaft Co., we use the term “drivetrain” to refer to all sequential components of the driveline, plus the transmission.
Key Parts of a Driveline
Four components comprise the driveline: the driveshaft, the differential, the axles, and the wheels.
Not one of these parts are optional. Each serves a function in the process of directing energy from the engine/transmission, using it, and moving the vehicle.
Driveshaft
The driveshaft is a mechanism shaped like a narrow, cylindrical rod, typically composed of:
● 1 rotating tube (or “shaft,”)
● 1 slip spline or slip joint (to enable telescoping)
● 1-3 joints or couplings (typically U-joints, yokes, or flanges)
The driveshaft receives power from the vehicle's transmission as a twisting force called torque. It rotates, carrying the torque force and transmitting it to the differential, by way of its universal joints or couplings. These connectors are at the shaft’s ends.
Differentials
Differentials are mechanical, gear-based devices that regulate the power as it moves through the driveline.
They deliver differing amounts of power via output shafts as needed, thus enabling the different wheels on a vehicle to rotate at different speeds. This differentiation is crucial to making safe turns.
Axles
An axle is a rotating rod composed of a shaft, bearings, and hubs. It transfers energy from the differentials to the vehicle's wheels. The vast majority of drivetrains have two axles: front and rear.
Wheels
Wheels receive energy from the axles, and they rotate to propel the car or truck. The rotational force of the wheels must meet the ground, creating a frictional force called traction, to push or pull the vehicle.
Types of Drivelines
Most cars and trucks utilize drivelines with one of the following three configurations.
Front Wheel Drive (FWD)
FWD drivelines deliver power solely to the vehicle’s front two wheels. The auto’s movement depends on the front wheels pulling the rest of the vehicle.
It's slightly more fuel-efficient than other configurations. As a result, it's a popular setup in compact cars (like the Toyota Hatchback) SUVs (like the 2025 Chevrolet Trax), and minivans (like the Honda Odyssey).
Rear Wheel Drive (RWD)
RWD exclusively delivers power to an auto’s back wheels. When an RWD vehicle drives forward, it's being pushed by its back wheels.
This enhances the vehicle's weight distribution and balance, which makes it easier to handle a car or truck that could be challenging otherwise. Thus, it's a popular driveline configuration for pickup trucks (like the Ford F150) and luxury cars (like the Ferrari 488 Pista).
All-Wheel Drive (AWD / 4WD)
AWD drivelines direct power to all four wheels, either full-time or only when extra frictional force is necessary.
AWDs make vehicles easier to handle and improve their off-road performance. Some manufacturers distinguish between AWDs and four-wheel drivelines (4WDs), applying the 4WD label to vehicles designed specifically to handle extreme conditions.
That said, AWDs aren't as fuel-efficient as their RWD and FWD counterparts. So, these drivelines are generally only used in higher-end trucks (like the Freightliner M2 106) or SUVs built for off-road adventure (like the Jeep Wrangler).
Top 8 Most Common Driveline Issues
Do you know how well your drivetrain is working? Here are eight signs it might be in trouble.
1. Strange Noises
Unusual sounds are one of the most frequent signs of a driveline in trouble.
If you hear abnormal vibrations; clanking or "thunk" noises when gears shift; or high-pitched, "windy" whines in your car, get your drivetrain checked out.
2. Fluid Leaks
Fluid leaks can be a sign of driveline damage. They can also cause driveline damage. If you see drips or puddles of either transmission fluid or oil, it's time for a patch-up.
3. Gearshift Troubles
Your auto's transmission and the gears of the clutch are crucial for shits. Slipping and hard-shifting are signs of a problem.
4. Drifting and Pulling
The default forward motion of a car or truck should be straight on. When it drifts or pulls to one side of a lane, the driveline's wheels' tires may have worn down unevenly.
It might also stem from poor alignment, which is often an effect of underlying driveline issues.
5. Weak, Shuddering, or Unresponsive Acceleration
If your vehicle is slow to respond to acceleration, chances are there's a glitch or break in the smooth transfer of engine power through the driveline. Shuddering during acceleration indicates force is not being efficiently and evenly distributed. Both point to potential driveline damage.
6. Turning Trouble
When a vehicle doesn't turn readily, it often has an issue with the driveshaft. If a joint is degraded or broken, it won't direct the wheels effectively.
7. Burnt or Foul Odor
Bad smells are an urgent warning sign of driveline problems. Keep particularly alert to sulphuric or "burnt" scents. These can indicate crucial drivetrain parts are overheating, or even burning, due to insufficient regulation of the engine's energy.
8. Visual Dashboard Warnings (Lights)
Does your dashboard have specific indicator lights to warn of traction control, ABS, or transmission problems? If so, don't ignore them! Bring your auto in for repair as soon as the light goes on.
How to Address Common Driveline Issues
When you need to address driveline issues, it's time to call in the experts.
At Point Spring & Driveshaft Co., our professionals specialize in driveline systems. Each of our engineers and technicians is trained in precision diagnosis.
Moreover, we utilize state-of-the-art machine technology to fabricate, repair, and fit your vehicle with the exact components it needs. Whether you just need to replace a u-joint, or you need a wholly customized shaft, we've got your drivetrain covered.
Maintaining Your Driveline for Longevity
Just like there's more to being healthy than getting antibiotics when you're sick, there's more to your vehicle's health than getting repairs when something breaks. Instead, get into good auto maintenance habits.
Inspection
In general, it's wise to inspect your vehicle's driveline regularly. You might inspect it when you change the differential fluid, ideally every 30,000-60,000 miles. Your owner's manual should indicate the specific mileage for your model.
Replacements
Timely replacements mitigate the risk of damage to the vehicle as a whole as parts experience wear and tear.
The average driveshaft should be replaced every 75,000 miles, while it's smart to replace tires every 6 - 10 years.
Likewise, car axles are usually good for up to 60,000 miles, but trailer axles should be replaced every 3-5 years.
Point Spring Specialists Deliver Driveline Expertise—Fast
You know what a driveline is, and, more than that, you understand the crucial impact the driveline has on how well your car or truck runs.
If you're having driveline trouble—or any other auto troubles or questions—connect with our experts. Give us a call at 888-787-7746, or fill out the form below. We're Point Spring & Driveshaft Co., and we're here to help.