Vehicle suspension and steering systems could be relatively simple if cars only drove down straight, perfectly flat roads. Unfortunately, real life rarely takes people in straight lines. Instead, manufacturers need to account for imperfect and curvy roads. CV (constant velocity) joints allow your engine to transmit rotational energy to the wheels, even as the wheels turn and bounce.

Depending on your car's drive configuration, you may only have CV axles on the front or rear wheels. AWD vehicles typically have CV axles on the front and back since they need to transmit power to all four wheels. Wherever your car may have them, it's crucial to recognize the signs of failure and never ignore a CV axle that's on its way out.

The Symptoms of CV Axle Failure

The CV joints on a CV axle are filled with grease to keep the bearings moving slowly and ensure they don't immediately fail due to friction and heat. Each axle has two joints: one at the wheel and one at the transaxle or differential. The typical CV axle design uses rubber boots to cover and protect the joints, protect the bearings from contaminants, and keep the lubricant contained.

As with any other component, there are weak points in this design. The most common failure point is with the rubber boots. A tear or hole in one of the rubber boots can allow moisture or dirt to contaminate the joint. Since the CV axle is rapidly turning, this will produce friction and heat. The damage will also usually allow most of the lubricating grease to escape.

The most common initial symptom of a bad CV joint is a clicking or clacking noise. You'll hear this sound as you turn, and it will usually go away when you turn the wheel back to the center. You may also see some grease on your wheels, although this isn't as common and won't be visible if the inner joint fails.

The Consequences of Ignoring a Bad CV Axle

Ignoring a bad CV axle for long enough can cause the joint to fail. When a CV axle joint fails, it can separate at the joint. This situation can cause catastrophic damage, allowing the axle to flop around and damage suspension components or even ruin your transmission. If the axle fails while you are driving, you may even lose control of the vehicle.

Since the consequences of catastrophic CV joint failure can be so severe, it's crucial to recognize the symptoms and address them as soon as you can. If you can hear the telltale clicking of a faulty joint as you turn your wheel, schedule a visit with a mechanic for auto repair services as soon as you can. The cost of a new CV axle will ultimately pale compared to the damage that a failed joint can cause.