Your engine transforms fuel and air into horsepower, which can be transferred to the wheels with the aid of additional parts. While CV axles permit the transfer of energy to the wheels that help the vehicle move while simultaneously allowing up and down movements, they are instrumental in steering.
Despite their importance, CV axles, like every other component in a vehicle, will ultimately fail. Their failure could lead to costly downtime until it is fixed, and that’s why detecting signs of failure is essential.
Here’s how to tell if your CV axle is bad, different ways of inspecting them, and the possible repercussions of neglecting the problem.
What Are CV Joints?
CV joints, or Constant velocity joints, as they are sometimes called, are located on the tips of the drive shafts. They are required for attaching the drive shafts to the transmission and wheels. Due to their job, their position and movement range, these joints have a high possibility of failing.
Like any other device used by a vehicle, they can also break. Understanding how these joints function will help expand your knowledge base on how crucial these parts are to the vehicle.
There are two types of CV joints: the Cardinal type, which is generally seen on heavy duty trucks and 4WD vehicles and rzeppa CV joints, which are seen on the majority of front-wheel drive cars.
Function
The CV joints serve the purpose of suspending the drive shaft, as well as transferring power to the wheels from the gearbox. In short, if you step on the gas, your wheels will spin.
If the CV joint malfunctions, it can adversely affect the driving functionality of the vehicle. During a gear change, there will often be a distinct ‘popping’ or ‘clunking’ noise coming from the gearbox which means that something is amiss.
The vehicle will suddenly cease to move if the joint gets fully detached, which will also cause damage to other parts of the vehicle. This aspect of your car is of critical importance and should therefore be checked regularly.
Symptoms of a Bad CV Joint
When a CV joint goes bad, the most simple sign are knocking sounds while accelerating and turning at the same time. It could also be due excessive vibrations experienced from the suspension, or steering problems. Other failure scenarios include difficulty controlling the vehicle.
Other common signs of a bad CV joint include the following:
#1. Vibration While Driving.
This one is particularly tricky due to the host of factors that could be responsible for vibrations while driving. On the other hand, unusual vibrations that are excessive, worsen with increased speed, or tend to ‘bounce’ while you drive could be caused by the CV axle.
Regardless of the cause, any such vibrations are bound to have a negative effect on your vehicle’s overall functionality and control, highlighting the importance of a vehicle inspection.
#2. Grease on the Inside or Edge of the Tires.
When the CV axle joint spins, the grease is kept from leaking by a boot. Assuming the boot gets a leak, the resulting friction could easily damage the CV joint, leading to complete failure.
If you see grease on the edge of your tire or the inner circle of the wheel, don’t postpone your car for servicing.
#3. A Knocking Sound.
Be vigilant for any kind of rhythmic clunking or knocking – while this sound is not solely the result of the CV axle, it is highly advisable to investigate further to see what the underlying causes could be and fix immediately.
You might find that the banging noise is more notable in the reverse gear in some instances. For the most part, your greatest option is hiring a professional to look at the issue as soon as possible.
In case you are unsure how safe the vehicle is to operate, don’t hesitate to reach out to us. In case it is needed, we will talk you through the problem and organize everything.
#4. “Clicking” Noises When Turning.
When changing directions, the car produces a “click” sound that many might compare to a pop. It’s produced from the slack of a CV axle that is worn out, and it makes itself obvious when the car turns. Like all other symptoms, this sound signals that it is time for a service center visit.
#5. A Tear in the Boot.
This one is rather obvious, though the majority of other symptoms could have other plausible explanations; nonetheless, sometimes it is advisable to follow the signs when they lead you towards a certain direction.
Put simply, if you notice many indicators pointing towards what seems to be a blown CV axle, there is a single definitive approach to confirming the issue: look at the axle. To do this, you must slide underneath your car to see the CV axles linked to the wheels.
If the rubber tear of the boot is noticed, it will surely need to be replaced. Most of the time, that’s sufficient. On the contrary, if the torn boot is not tackled on time, the ungreased joint can get spoiled. At this point, it is advisable to replace the entire CD axle.
How to Diagnose a Bad CV Axle: 2 Quick Tests
There are other issues that could be caused by other parts like, a worn wheel bearing, which can mimic almost all the symptoms caused by a bad CV axle. This is the reason it is crucial to diagnose other problems before assuming the CV shaft is the problem.
What you have to do is the following:
1. Perform a Visual Inspection
Your primary focus should be on the CV axle. Should the axle appear intact, see whether the CV boot is ripped apart. If that is the case, there is potential that the CV joint is failing which may cause axle failure.
In this instance, the most appropriate suggestion is to completely replace the entire CV axle assembly in order to mitigate any issues with the axle.
2. Go for a Test Drive
If all the axle joints and boots seem to be intact, the next course of action is to test drive the vehicle in a parking lot. To begin, reverse the car while turning the steering wheel to a particular side and then drive in a circular motion towards the rear.
Then, do the procedure again while rotating the steering wheel in the opposite direction. If there is a strong clicking sound, then there is a high chance that the outer CV joint has worn down. In that case, CV joint repair is necessary.
To determine the condition of the inner CV joint, reverse the car while applying the gas and letting off of the gas. A consistent thumping sound means the axle is damaged along with the inner CV joint which means you need to replace the CV joint.
With the identification of a broken CV axle comes the understanding of the safety risks involved.
CV Joint Replacement Cost
When having a CV axle replaced, a repair shop will typically charge somewhere between $250 and $500. The price greatly fluctuates due to the specific car model and the repair shop’s labor costs. For parts, the price is generally between $60 and $150, while the labor fee ranges between $180 and $350.
Only a certified mechanic with the right set of skills and tools will be able to perform a complete installation of a CV axle, which may take him between 1.5 to 3 hours.
A CV joint repair, on the other hand, will cost around $1,117 and $1,165, with estimates for labor costing between $181 and $228 and parts between $936 and $937, in total. In this regard, an entire CV axle assembly is cheaper in comparison because most mechanics will opt to install new parts instead of maintaining the CV joint.
Your place of residence will influence how much these costs will increase in the future due to new demands in tax or charges. Other relative repairs may be needed also to fix the underlying issue.
How Long Do CV Joints Typically Last?
Considering the average lifespan for a CV axle is set at approximately 100,000 miles, the points of failure are most often associated with a problem somewhere along the boot, which causes it to leak.
If the CV joint is fitted within a protective boot, CV joints on some vehicles can reach a mileage of above 300,000 miles while still retaining the original CV joint.
How Long Can I Go with a Bad CV Axle?
To put it bluntly, driving with a defective CV axle joint is dangerous. If you notice your car is exhibiting any symptoms of a damaged CV joint, the best thing you can do is take it to a garage shop or attend to the joint yourself.
Ensure that once the CV boot has been torn, it is only a matter of time before the axle will inevitably fail. Not doing anything about it will lead to an extraordinary failure of the axle, which, as mentioned before, is a moving part.
When it fails, it will keep on best trying to revolve, smashing into anything in its way. Checking the incidence of CV joint / axle failure on a regular basis is the most efficient way to avoid problems.
If you take your vehicle in for an oil change, make sure to ask the oil technician if he would not mind having a look at the CV boots for problems. Normally, it is not part of a standard inspection, but when they are under the vehicle, it takes a very short amount of time to check it.