Bad CV axle symptoms include a clicking noise when turning, especially while accelerating; vibration or shudder when accelerating; grease sprayed on the inside of the wheel or suspension from a torn boot; and a clunk when shifting into drive or reverse or when getting on and off the throttle. CV axles drive the front wheels on front-wheel-drive cars and appear at all four corners on many all-wheel-drive vehicles and some trucks.
Symptoms by joint
| Joint | Typical symptoms |
|---|---|
| Outer CV joint (wheel end) | Clicking on sharp turns, louder when accelerating; see clicking noise when turning |
| Inner CV joint (transmission end) | Vibration or shudder under acceleration that eases when coasting; see car shakes when accelerating |
| Torn boot | Grease flung around the wheel well; early warning before noise |
| Worn axle splines or joints | Clunk when changing from drive to reverse or on and off the throttle |
Bad CV axle symptoms while driving
While driving straight, a worn inner joint can cause a vibration that rises with acceleration and fades when you lift off. Outer joints are usually quiet in a straight line and click only in turns. A failed axle can stop transmitting power entirely, leaving the engine revving with no movement on that side; see car won’t move in drive.
Bad CV axle symptoms when braking
CV joints are not normally loud under braking. A noise when braking is more likely brakes, wheel bearings or suspension bushings; see grinding noise when braking and car pulls when braking.
Inspecting CV axles
- Turn the steering to full lock and look at the outer boots for tears, cracks and grease.
- Check the inner boots near the transmission or differential.
- Grab the axle and check for excessive clunking play at the joints.
Replace the boot or the axle?
A torn boot caught early, before dirt and water have worn the joint, can be replaced with a boot kit. Once the joint clicks or the grease is contaminated, replacing the complete axle is usually quicker and more reliable.
How long CV axles last
A CV axle with intact boots often lasts a very long time. Most failures start with a torn boot that lets grease out and dirt in, so the boots are worth checking at every oil change or tire rotation.
Lifted and lowered vehicles
Raising or lowering a vehicle increases CV joint angles, which speeds up boot and joint wear and can cause vibration. Keep angles within what the parts are designed for; see clunking noise over bumps.
Related
For rear-wheel-drive trucks with driveshafts, see U-joint symptoms; for bearings, see wheel bearing noise.
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