Your engine turns air and fuel into horsepower, but to get it to the wheels takes additional parts. The CV axles are the parts that move that energy to the wheels where they can make your vehicle move while allowing them to turn and move up and down.
But CV axles aren’t always going to last a vehicle’s lifespan. When they fail, it can put you out of business until it’s fixed, so early detection is key. Here’s how to tell if your CV axle is bad, ways to check them, and what could happen if it isn’t fixed.
What Are CV Joints?
Constant velocity joints, better known as CV joints, are found at the ends of the drive shafts. They are essential to connecting the drive shafts to the transmission and wheels. Because of their function and location, these joints easily wear out over time.
They can even break. To ensure that you understand the importance of them, it helps to know a little more about what they do and what happens when something goes wrong with them.
There are two types of CV Joints. The Cardinal, which is usually found in heavy trucks and four-wheel drive vehicles and rzeppa CV joints found on most front wheel drive vehicles.
Function
Besides just holding the drive shaft in place, the CV joints also transfer power to the wheels from the transmission. Basically, they ensure that when you press on the gas, your wheels will turn.
If the CV joint is not working properly, it may affect the way your vehicle handles. Often you will hear a popping or a clunk sound when shifting, which indicates something is wrong.
If the joint breaks, it can stop the car from moving and can cause severe damage, making it essential component in your vehicle that needs to be kept in good condition.
Symptoms Of A Bad CV Joint
The most common symptom of a bad CV joint is knocking noises while turning and accelerating simultaneously. You may also notice excessive vibrations from the suspension or other issues with the steering. You may also notice other issues controlling the vehicle.
Here is a more detailed list of the signs of a bad or failing CV joint to look for:
#1. Vibration While Driving.
This is a tricky one, since there are many things that could cause vibration when you drive. However, if the vibrations are excessive, increase with speed, or give an unusually “bouncy” feel to your drive, it may be due to the CV axle.
Whatever the cause of vibrations, it’s important to get your vehicle inspected; if it vibrates too much, it can become harder to control.
#2. Grease on the Inside or Edge of the Tires.
The CV axle joint has boots that contain grease while the axle spins, keeping it from leaking. If the boot develops a leak, the resulting lack of lubrication could soon lead to the failure of the CV joint.
If you notice grease on the edge of your tire or the inside of the wheel, don’t wait to bring your car in for service.
#3. A Knocking Sound.
Keep an ear out for a knocking or clunking sound, especially a rhythmic one. While this doesn’t always come from the CV axle, none of the potential causes are good ones, so an immediate inspection is required.
In some cases, you may notice that the knocking sound is more pronounced in reverse. Ultimately, your best bet is to have the experts inspect the problem right away.
If you’re not sure how safe the vehicle is to drive, give us a call. We’ll discuss the issue with you and help make arrangements if necessary.
#4. “Clicking” Noises When Turning.
Though it’s sometimes described as a loud click and sometimes described as a pop, this noise is unmistakable once you hear it. It presents itself when you turn the vehicle, and it’s due to the loose joints of a worn CV axle. As with other symptoms, it’s important to bring your vehicle to a service center immediately if you hear this noise.
#5. A Tear in the Boot.
This is fairly obvious, but most of the other symptoms here could potentially have alternate causes; however, if all signs point north, it’s best to walk north.
In other words, if you exhibit several signs of a blown CV axle, there’s always one sure way to find out: inspect the axle. In order to do this, you’ll need to crawl under your vehicle to inspect the CV axles that connect to your wheels.
If a tear in the rubber boot is found, it will need to be replaced. Often, that’s all that’s needed. However, if a torn boot isn’t addressed quickly, the joint can run without grease and be damaged as a result. At that point, replacing the entire CD axle is typically best.
How to Diagnose a Bad CV Axle: 2 Quick Tests
Issues with other components, such as a worn wheel bearing, can mimic many symptoms of a bad CV axle. So, before jumping to conclusions, it’s important to confirm that the culprit is indeed the CV shaft.
Here’s what you need to do:
1. Perform a Visual Inspection
Start by visually inspecting the CV axle. If it looks undamaged, check if the CV boot is torn. If so, there’s a good chance you have a failing CV joint, potentially leading to axle failure.
In this case, the best thing to do is replace the entire CV axle assembly to avoid axle failure.
2. Go for a Test Drive
If you can’t see anything wrong with the axle joints and boots, the next thing to do is drive the vehicle in a parking lot. Start by reversing the vehicle, turning the steering wheel to one side, and driving backward in a circle.
Repeat the process by turning the steering wheel in the other direction. If you hear a pronounced clicking noise, the outer CV joint may be worn, and you’ll need a CV joint repair.
To check the inner CV joint, drive the vehicle in reverse while accelerating and decelerating. A clear clunking sound suggests a bad axle and an issue with the inner CV joint.
Once you’ve diagnosed a bad CV axle, it’s crucial to understand the safety implications.
CV Joint Replacement Cost
Replacing a bad axle costs between $250 and $500 at an auto repair shop, depending on the vehicle and labor rates. Parts typically range between $60 and $150, while labor should be roughly $180 to $350.
Installing a new CV axle takes roughly 1.5 to 3 hours and is best left to a skilled mechanic with the required expertise and tools.
On the other hand, a CV joint repair is between $1,117 and $1,165. Labor costs are estimated between $181 and $228 while parts are priced between $936 and $937. That’s why mechanics usually suggest replacing the entire CV axle assembly rather than fixing the joint.
This range does not include taxes and fees, and does not factor in your unique location. Related repairs may also be needed.
How Long Do CV Joints Typically Last?
On average, a CV joint is made to last about 100,000 miles and failure is most often associated with boot failure which causes it to leak.
However, if the protective CV joint boot isn’t damaged, a CV joint can last a very long time, with some cars reaching over 300,000 miles on original CV joints.
How Long Can I Go with a Bad CV Axle?
In the simplest terms, it is risky to drive with a bad CV joint on an axle. If you discover your vehicle is suffering any of the signs of a bad CV joint, the best thing you can do is get it to a mechanic as quickly as possible or replace the joint itself.
Remember that once the CV boot gets torn, it’s only a matter of time before the axle fails. Failing to address the situation can lead to catastrophic failure of the axle, which as stated above, is a part that is in rotating motion.
When it breaks, it will continue at its best to try to rotate, knocking into anything it can. The best method of prevention of CV joint / axle failure is to inspect often. If you take your car in for oil changes, ask the oil tech if he can quick the CV boots for you for issues.
It’s often not on a normal inspection, but while they are under-car, it takes less than 2 minutes to look each one over carefully.