Driveshaft vs. Tailshaft: Are We Speaking the Same Language?

Most people don’t give much thought to what’s happening under their car—until something goes wrong. That strange vibration at highway speeds, the sudden clunk when shifting gears, or the unsettling shudder when taking off from a stop could all point to a problem with one of the most critical yet often overlooked components of a vehicle’s drivetrain. 

For Australians, this component is called a tailshaft—a term that makes perfect sense given its position at the tail end of the drivetrain. But in the US, it’s known as a driveshaft, which can create confusion when sourcing parts or discussing vehicle maintenance. And to make things even trickier, what Australians refer to as a driveshaft is an entirely different part—one that connects the differential to the wheels. 

Understanding the differences between a tailshaft and a driveshaft isn’t just about terminology—it’s about knowing how power moves through a vehicle and what happens when things go wrong. Whether you’re an enthusiast modifying your car, a mechanic working on customer vehicles, or just someone trying to make sense of an online parts catalogue, getting it right matters. 

Understanding the Tailshaft and Driveshaft in Australia 

Before diving into the terminology debate, let’s first clarify exactly what these components do. If you look at the diagram below, you’ll see how a tailshaft connects the transmission to the differential, transmitting power to the rear wheels. This is a crucial part of rear-wheel-drive (RWD) and all-wheel-drive (AWD) vehicles, ensuring that engine power gets to the ground effectively. 

Meanwhile, the driveshaft (in Australian terms) is what connects the differential to the wheels in vehicles with independent rear suspension (IRS). These shafts, often featuring constant velocity (CV) joints, allow the wheels to move up and down while still receiving power. 

Understanding the Tailshaft and Driveshaft in Australia 

For Australians, the term tailshaft has been around for decades, but depending on where you are in the world, the name might not mean much. Across the Pacific, in the US, the same component responsible for connecting the gearbox to the differential is called a driveshaft. Different words for the same thing. 

Here’s what creates a lot of confusion, especially when reading American sources. What we in Australia call a driveshaft (the shaft that transfers power from the differential to the wheels), over in the US they call this the axle shaft or half-shaft. 

It’s more than just a case of regional slang. If you’re ordering parts, discussing repairs, or explaining an issue to a mechanic, getting the terminology right makes all the difference. The wrong word could see you waiting on the wrong part or misunderstanding a critical drivetrain issue. That’s why knowing how these components work—and what they’re called—matters, whether you’re an enthusiast fine-tuning your car or a driver just trying to keep things running smoothly. 

The Australian vs. American Driveline Terminology 

Understanding these differences ensures you don’t order the wrong part, especially when dealing with overseas suppliers. 

The Difference Between an Australian Tailshaft and a Driveshaft 

A tailshaft is only found in rear-wheel-drive (RWD), all-wheel-drive (AWD), and four-wheel-drive (4WD) vehicles. It connects the transmission to the differential, ensuring power reaches the driven wheels. 

Tailshaft in a 2WD Car 

In a two-wheel-drive (2WD) car, the driveline layout depends on whether it is rear-wheel drive or front-wheel drive. 

• In a rear-wheel-drive sedan or ute, the tailshaft is a straightforward component that connects the transmission to the differential. It consists of a single or two-piece design, with universal joints (U-joints) or a centre bearing to accommodate drivetrain movement. The tailshaft’s role is to transmit engine torque from the gearbox to the differential, which then distributes power to the wheels. 

• In a front-wheel-drive (FWD) car, the setup is completely different. Instead of a tailshaft, these vehicles use driveshafts (axle shafts) connected directly to the transaxle (a combined transmission and differential unit) to power the front wheels. These driveshafts incorporate constant velocity (CV) joints, which allow for smooth power delivery while accommodating suspension movement and steering angles. Since the powertrain is positioned at the front, there is no need for a long tailshaft running to the rear of the vehicle. 

Tailshaft in a 4WD or AWD Car 

In a four-wheel-drive (4WD) or all-wheel-drive (AWD) vehicle, the tailshaft serves a similar purpose but with added complexity. These vehicles typically have two tailshafts—one transmitting power to the front differential and another to the rear. In some cases, a transfer case splits power between them, ensuring proper torque distribution across all four wheels. 

How the Driveshaft Differs 

While the tailshaft handles power delivery from the transmission to the differential, the driveshaft (axle shaft) takes over from the differential, delivering power to the wheels. These shafts, equipped with CV joints, allow the wheels to move independently while maintaining smooth power transmission. 

Tailshaft vs. Driveshaft: Key Differences 

What Makes a Good Tailshaft? 

A well-functioning tailshaft ensures: 

• Efficient power transfer – Smooth torque delivery from the engine to the differential. 

• Minimal vibration – A properly balanced tailshaft helps prevent shuddering and premature wear on drivetrain components. 

• Durability under load – Whether you’re towing, off-roading, or chasing quarter-mile times, your tailshaft needs to handle the torque. 

Common Tailshaft Materials 

Tailshafts are built from different materials, each with its own advantages: 

• Steel – Strong and cost-effective, used in most factory vehicles. 

• Aluminium – Lighter than steel, reducing rotational mass and improving acceleration. 

• Carbon Fibre – Ultra-lightweight and high-strength, common in high-performance applications. 

How to Spot a Failing Tailshaft 

A worn-out tailshaft can cause serious drivetrain issues. Some telltale signs include: 

• Vibrations at high speeds – This usually means the tailshaft is out of balance or has worn U-joints. 

• Clunking noises when accelerating – Could indicate a worn slip yoke or failing U-joint. 

• Shuddering when taking off – A worn-out centre bearing could be the culprit. 

• Excessive play in the driveline – This often suggests worn splines or damaged joints. 

Ignoring these warning signs could lead to catastrophic drivetrain failure, so it’s worth checking if you notice any of them. 

Why It Matters on the Road 

Understanding the difference between a tailshaft and a driveshaft is crucial, whether you’re working on your own vehicle or explaining it to someone else. In Australia: 

• A tailshaft connects the transmission to the differential. 

• A driveshaft (axle shaft) transfers power from the differential to the wheels in IRS setups. 

Keeping your drivetrain well-maintained ensures smoother performance and prevents costly failures. Whether you’re after a replacement tailshaft, a custom-built setup, or expert advice, GJ Drivelines has the expertise to keep your car running at its best. 

Further Reading 

See the GJ Drivelines page “Tailshaft and Driveshaft FAQs for Every Car Owner”  
https://gjdrivelines.com.au/tailshaft-driveshaft-faqs-car-owners/