CV Axle vs. Driveshaft: What’s the Difference (and Which One Is Failing)?

If you’ve ever experienced clicking noises while turning or vibrations under acceleration, you may be dealing with a failing CV axle or driveshaft. These parts are critical to transferring power from the transmission to the wheels, but many drivers don’t fully understand how they differ. At GSP North America, we specialize in premium suspension and drivetrain components, and we want to help drivers understand how to tell these parts apart, what symptoms indicate failure, and when to seek a replacement.

What Is a CV Axle?

CV stands for constant velocity, and CV axles are designed to transfer power from the transmission or transaxle to the wheels in a way that accommodates steering and suspension movement. They are common in front-wheel-drive and all-wheel-drive vehicles. Equipped with CV joints at either end, these axles maintain smooth rotation at consistent speeds even while the wheels are turning or the suspension is moving over bumps. They are protected by flexible rubber boots filled with grease, which keep the joints lubricated.

What Is a Driveshaft?

Driveshafts serve a similar purpose but are typically found in rear-wheel-drive, four-wheel-drive, and some all-wheel-drive vehicles. The driveshaft is a long tubular component that transfers torque from the transmission to the differential, which then sends power to the wheels. Instead of CV joints, driveshafts use universal joints, or U-joints, which allow for movement and flexibility as the vehicle drives. The design makes driveshafts robust and capable of handling the higher torque demands of larger vehicles.

Symptoms of a Failing CV Axle

The most common symptom of a failing CV axle is a clicking or popping sound when making turns, especially at lower speeds. This is often caused by worn CV joints. Another sign is grease leaking from a torn CV boot, which leaves the joint exposed to dirt and debris, accelerating wear. Drivers may also notice vibrations during acceleration or a knocking sound near the wheels. Left unaddressed, a failing CV axle can eventually fail completely, preventing power from reaching the wheels.

Symptoms of a Failing Driveshaft

A failing driveshaft presents differently. Clunking noises when shifting gears, vibrations under the vehicle, or difficulty turning can indicate driveshaft issues. Worn U-joints often cause squeaking noises that get worse with speed. In severe cases, a failed driveshaft can disconnect power completely, leaving the vehicle unable to move.

Why These Failures Are Dangerous

Both CV axle and driveshaft failures present serious risks. A failing CV axle may snap during operation, cutting power to the wheel and leaving the vehicle stranded. A broken driveshaft can cause sudden loss of power and may even damage other parts of the drivetrain. In either case, driving with these symptoms compromises control and safety.

Replacement Tips

Inspect boots and joints regularly for signs of wear. Always replace with OEM-quality or better components to ensure reliability. Driveshafts should be balanced properly during installation to prevent vibrations, and CV axles should always be replaced as a complete unit to ensure durability.

Conclusion

Though CV axles and driveshafts perform similar roles, they are distinct components with different designs and failure modes. Knowing the signs of trouble can help you prevent breakdowns and expensive repairs. At GSP North America, we manufacture CV axles and driveshafts engineered for strength, performance, and long-term reliability. Visit our catalog today to find the right replacement part for your vehicle.