CV axles are most commonly used on front-wheel-drive vehicles to transfer engine power to the wheels. Some all-wheel-drive vehicles and rear-wheel-drive vehicles with independent rear suspensions also use CV axles to transfer engine power to the wheels.
CV axles have an inner joint and an outer joint. Either of the two CV joints on an axle can be replaced separately, if necessary. That involves removing the axle, removing the axle boot and then the joint, installing a new joint, new grease and the boot, then reinstalling the axle in the vehicle.
But this is generally never done due to the cost factor.
If a CV joint has failed, then, 99% of the time, replacing it with a new axle will be recommended. For whatever reason, whether using OE parts or aftermarket, pre-assembled CV axles generally cost about the same (or often less) as a single CV joint.
General Cost of CV Joint Issues
It’s not that difficult to get an average cost for a car’s CV axle replacement, as most axles are generally built similarly, they also cost about the same, and even the replacement procedure for most vehicles is quite similar. Most shops in the UK will use a standard charge for axle replacement rather than come up with specific estimates for specific vehicles.
On average, it costs around £250 to replace a CV axle on most vehicles. That’s without a wheel alignment, which might or might not be necessary depending on how the work is done.
An experienced mechanic can usually do CV axle replacement in a way that doesn’t disturb the wheel alignment, though that offers no guarantee that the alignment was good enough before he replaced the CV axle. It’s recommended to at least check the alignment afterward, and it’s usually done free of charge. If at all necessary, the cost of alignment would be additional.
Some more specific examples of the cost to replace a CV joint or axle on some common vehicles using a £70 per hour labour rate are as follows:
|Car Model||Labour Time & Cost||Aftermarket CV Axle Cost (Excl. Labour)|
|2007 Honda Accord Automatic (3L engine)||£90 (1.3 hrs)||£100 approx.|
|2006 Volkswagen Jetta||£90 (1.3 hrs)||£100 approx.|
|2009 Dodge 1500 4WD||£60 (0.9 hrs)||£100 approx.|
|2004 Toyota Corolla||£170 (2.4 hrs)||£100 approx.|
The above CV axle estimates rely on book time; many shops will replace axles at a standard charge on most vehicles rather than book time, which is usually calculated at a flat hourly rate.
PRO TIP – Quite often, axles are sold with a core price attached (around £30 or £40), which is returned when the old part is turned in. Usually, that is taken care of by the repair shop and is only an issue if the old axle is damaged in such a way that it has no core value left.
New Versus Remanufactured CV Axles
For many years, depending upon the vehicle, new axles were only available through dealer sources and only remanufactured axles were commonly available in the aftermarket. Most of the time, a new axle is the best choice, but looking at the CV joint pricing differences above, many times it comes down to cost.
In the last few years, there has been much better availability of new aftermarket axles on many vehicles. Usually, there isn’t much of a price difference between a new and a remanufactured aftermarket CV axle, and if a new axle is available, that’s usually the best choice.
Other Cost Things That Might be Recommended
On most CV axles, there is an axle seal at the juncture where it slides into the body of the transmission. In general, if that seal wasn’t leaking before the axle replacement, it probably won’t leak after the replacement either.
But the seal is easy to damage during installation and is usually insignificant in cost, especially when compared to the cost of a double-axle joint replacement.
PRO TIP – The cheapest time to replace an axle seal is when the axle is out, and it’s not a bad idea.
A wheel alignment will be recommended after the axle replacement. Generally, the thumb rule is that if any part of the suspension between the wheels is removed or replaced, the alignment should be checked.
On most cars, when replacing an axle, you must disconnect the lower ball joint. Sometimes the entire knuckle must be removed, and sometimes the knuckle is disconnected at the strut. In any case, if an alignment is recommended, it’s probably a good idea to have it checked.
PRO TIP – Even if wheel alignment is not recommended, it’s still a good idea to pay attention to how the vehicle drives and if any difference is noted after the work, have the alignment checked.
The first and main signal of a change in toe angle (the primary angle involved in tyre wear) is a change in the position of the steering wheel when driving straight down a flat road. If the steering wheel was level before and after, then there was probably no change.
PRO TIP – If the CV joint failure was because of the inner joint, the engine mounts should be inspected and addressed as necessary.
If an inner joint has failed, always remember that these are sensitive to the engine position. The engine mounts hold the engine in place and absorb vibrations; if one is worn out, that changes the angle of the engine and, consequently, the angle of the CV joint.
If the engine mount that resists engine movement under force wears out, then the engine can roll forward or back too far. This can put the inner joints at more extreme angles than they were designed for, causing wear and tear and, finally, failure.
How CV Joints Fail
Generally speaking, CV joints use a rubber or silicon boot to hold the grease in the joint. Most CV joint failures begin with a split or torn boot – whether from ordinary wear and tear or getting torn from road debris. At that point, the grease starts oozing out and road grime can enter.
In some cases, if a torn boot is noticed early enough, the boot can just be replaced. More often, the joint has run too long without grease to be trusted or the joint has enough mileage on it that replacement is warranted for age and wear regardless.
PRO TIP – If a CV boot tears on an axle that has more than 100,000 miles on it, it’s usually most economical in the long run to bear the cost and just replace the whole CV axle.
Joints can also wear out if the boot is intact. What is commonly noticed on an outer joint on a front axle is a clicking noise when accelerating with the wheel steered fully one way or the other. At that point, the outer joint is under the most stress and wear will show up as noise following the wheel’s rotation.
The inner joint is under the most stress when accelerating – regardless of direction. Sometimes, wear patterns can develop in the tripod joint that prevent the smooth transmission of power.
Under heavy acceleration, a worn tripod joint can feel like a front-end vibration or a distinctive oscillation in the engine position, pushing and releasing the engine side to side in rhythm with the wheel’s rotation.
As with most things, it varies to a great extent with how the vehicle is driven. The axles transfer engine power to the wheels and are most often highly stressed depending on the driver’s relationship with the gas pedal. By way of an estimate, if an axle has trouble after about 1,00,000 miles has passed, on most vehicles we can safely say that the axle has had its full life. On a lightly driven vehicle, it’s not unusual to see axles last 1,50,000 miles or more.
No, you do not. A new CV axle on one side will work perfectly well with an old CV axle on the other side. There is no overlapping labour or typical discount for doing both axles instead of one. However, an argument could be made if one axle wore out completely and the other one too wasn’t far behind, and doing them both could save an eventual trip back to the shop.
One of the reasons that automobile mechanics are very conservative on this issue (or even reticent to answer this question at all!) is that the bearings in a clicking CV joint have already failed. In the worst case, a clicking axle can come apart completely, stranding the vehicle and potentially doing collateral damage as the broken axle spins. This writer had a caravan towed in years ago with a broken axle that had beaten a hole through the transmission case, for instance. Therefore, it’s almost impossible to find a mechanic anywhere who will tell you that a clicking axle is OK to drive on.
But liability concerns aside, it’s not uncommon to see a CV boot start to leak grease, and to be OK for a few thousand miles before the joint starts to make noise. And once that happens, it’s not uncommon to see that axle get very slowly and progressively louder over 10,000 miles or so, without breaking, as long as the driver goes easy on it. It’s still a problem best taken care of when it is noticed, but it is possible to nurse things along for a while.