What is a CV Axle?
A CV axle, or Constant Velocity axle, serves as a critical link in your vehicle’s drivetrain system. This component transfers power from your transmission (or differential) to your wheels while accommodating the up-and-down motion of your suspension and the turning of your wheels.
The typical CV axle consists of three main components:
- An inner joint that connects to the transmission or differential
- A solid shaft running between the joints
- An outer joint that connects to the wheel hub
How CV Axles Work
The CV axle’s unique ability is to perform multiple functions simultaneously. Its primary function is to transfer the rotational power from your engine and transmit the power to your wheels through its connection to a transmission or differential.
However, unlike a simple straight axle, CV axles must accommodate complex movements. When you turn your steering wheel, your front wheels pivot at an angle. A CV axle maintains constant rotational speed even as these angles change, ensuring smooth power delivery without binding or jerking.
Additionally, as your vehicle travels over bumps and dips in the road, your suspension system moves up and down. The CV axle must allow for this vertical movement while continuing to transfer power efficiently. This is particularly important during acceleration, when significant torque is being applied through the axle.
Think of the CV axle as a flexible connection that can bend and adjust while still maintaining its primary function of transferring rotational energy. This flexibility comes from the unique design of the constant velocity joints, which use ball bearings in special tracks to maintain consistent motion regardless of the operating angle.
Signs of a Failing CV Axle
Recognizing the symptoms of a failing CV axle early can save you from more expensive repairs down the road. Here are the most common warning signs to watch for:
Clicking noises when turning:
This is perhaps the most telltale sign of a CV axle problem. If you hear a clicking or popping sound that gets louder when making sharp turns (particularly when accelerating through a turn), it likely indicates a problem with the outer CV joint.
Grease leakage around the wheel area:
CV joints are protected by rubber boots filled with grease. If these boots crack or tear, you may notice dark grease splattered on the inside edge of your tire or on nearby suspension components. This is a serious warning sign, as once the joint loses its lubrication, failure will follow quickly.
Vibrations while driving:
A damaged CV axle can cause vibrations that you will feel through the floor or steering wheel, especially during acceleration. These vibrations may increase with vehicle speed and can sometimes be mistaken for tire balance issues.
CV axle attached to the vehicle’s chassis, but with the wheel removed
Consequences of Driving with a Bad CV Axle
Continuing to drive with a failing CV axle can lead to potential permanent damage to your vehicle.
Reduced Vehicle Control:
A severely worn or damaged CV axle can affect your ability to control your vehicle, particularly during acceleration or when navigating turns.
Potential Drivetrain failure:
If a CV joint fails while driving, it can cause the axle to break. This will immediately disable your vehicle, potentially leaving you stranded in an inconvenient or dangerous location.
Damaging Other Components:
A failing CV axle doesn’t exist in isolation. The vibration and irregular movement it creates can damage your transmission, differential, wheel bearings, and other drivetrain components, compounding your repair costs.
Steering & Suspension Services at Scott’s U-Save
Your vehicle is made up of a large number of components that all work together to get you safely to your destination. Steering components like tie rods ensure your car drives in a straight line. Like any part of a car, these components will eventually wear down over time and lose their effectiveness. Whether you need to replace worn-out axles or diagnose a weird noise coming from your car, Scott’s U-Save can help. We have four convenient locations in New Lenox, IL; Schererville, IN; Steger, IL; and Crown Point, IN, all staffed with ASE Certified technicians. Call or schedule online with us today!