A CV joint typically makes noise, often a clicking sound, because it is worn down and can no longer properly absorb vibrations and shocks.
CV joints, or constant velocity joints, are critical components of your vehicle's drivetrain, particularly in front-wheel-drive cars and many rear-wheel-drive and all-wheel-drive vehicles. Their main function is to allow the drive axle to transmit torque to the wheels at a constant speed, regardless of the steering angle or suspension travel. This complex task requires precision-engineered parts that move smoothly together.
Understanding the Clicking Sound
The most common noise associated with a failing CV joint is a clicking or popping sound, especially noticeable when turning.
According to sources: The clicking noise is caused by the CV joint at the end of the CV axle shaft. As the CV joint wears down, it becomes less able to absorb shock and vibrations. This can cause the clicking noise, as well as other problems like a vibration when you're driving.
Here's a breakdown of why this happens:
- Wear and Tear: Over time and mileage, the internal components of the CV joint (such as the cage, bearings, and races) can wear down due to friction and stress.
- Loss of Lubrication: The protective rubber boot surrounding the CV joint can crack or tear. This allows the lubricating grease to leak out and contaminants like dirt and water to get in. This accelerates wear significantly.
- Reduced Shock Absorption: As the internal parts wear, the tight tolerances within the joint are compromised. The joint loses its ability to smoothly handle the rotational forces and the varying angles it operates at, especially when turning or hitting bumps.
- Resulting Noise and Vibration: The looseness and friction in the worn components cause them to bind and release rapidly, creating the characteristic clicking or popping sound. This wear can also lead to noticeable vibrations felt through the vehicle.
Symptoms of a Failing CV Joint
Recognizing the signs of a worn CV joint is important:
- Clicking/Popping Noise: Most prominent when turning, but can also occur when driving straight, particularly under acceleration or deceleration, as the wear worsens.
- Vibration: A vibration felt through the steering wheel or the vehicle body, which may worsen with speed or when turning.
- Grease Leaks: Visible grease around the wheel, often slung onto the inside of the rim, indicates a torn boot allowing lubricant to escape.
| Symptom | Description | Common Trigger |
|---|---|---|
| Clicking or Popping | Repetitive clicking sound | Turning the steering wheel |
| Vibration | Shaking sensation in the vehicle or steering wheel | Driving at speed or turning |
| Grease Leak | Visible grease around the axle/wheel | Torn CV boot |
The Solution: Replacement
A noisy CV joint indicates significant internal wear. Since CV joints are not typically repairable, the standard solution is to replace the entire CV axle assembly or sometimes just the outer CV joint, depending on the vehicle and the location of the wear. Ignoring a noisy CV joint can lead to complete failure, potentially causing a loss of power to the wheel or even a safety hazard if the axle breaks.
