This morning, in the parking lot at work, a car made a right turn under power and I heard the unmistakable sound of a bad CV joint. From that sound alone, I would guess that the left (driver’s side) joint was bad since that side would have been fully extended.
When you have a bad CV and it makes that sound in a turn, is it always the extended CV, the contracted CV or is it not possible to know one way or the other.
Well for wheel bearings it’s almost always the outside wheel in the turn. CV joints? Not so sure. Seems that the inside would be slightly tighter in a turn.
However it shouldn’t be all that hard to diagnose. If the rubber boot around a CV joint is torn, chances are extremely good that’s the bad one. Probably needs to be replaced anyway as I’ve had little luck just replacing a boot especially with the split-boot replacements.
Otherwise just jack up the front of the car so both wheels are off the ground. Turn the steering wheel full lock in one direction. If front wheel or 4-wheel drive, put in neutral. Spin the tire by hand. If you feel a ‘clunking’ on one side, that could be the problem. Turn full lock the other direction and see how the wheels turn. Of course both outer CV joints could be bad.
BTW: I’m talking about the outside CV joint on an axle. I’ve never had a badly worn inner CV joint.
The CV joints don’t extend or contract with turns (they do a bit with bumps). On a tight turn, both outer joints are at or close to full flex (with the joint on the inside of the turn flexed a bit more than the one on the outside), and that’s the condition where the noise usually appears. Sometimes you can hear that the noise is clearly on one side, sometimes that’s not so clear. If it’s not clear, usually the symptom can be duplicated in the shop with the front end raised, full turn, in gear, and load on the front wheels (light brake application) so the mechanic can get his ears close enough to pinpoint the noise.
That’s true for the older designs with separate inner and outer bearings where the inner bearings seldom failed. Front wheel drive cars typically have a larger double bearing on each side with an inboard portion and an outboard portion housed in a common outer race piece. On these, the inboard portion can go bad and make noise when it’s on the outside of the turn, even though its wheel is on the inside of the turn. In other words, if the right inboard bearing – which is on the left side of the right wheel – goes bad, it will make noise on a right turn. With these designs, it’s necessary to identify the noisy side in the shop to avoid getting fooled.
Thanks for this! I drive a car with over 200K miles on it and have been suspecting the left front wheel bearings are going bad because of increased bearing-type noise on right turns, but now I’m not so sure based on you description. Although, I am pretty sure the noise comes from the left front corner of the car. I’ll be paying closer attention now.
Thanks again.
A technique I learned to identify noisy wheel bearings:
With the wheels in the air, spin each one by hand while keeping a finger on the suspension spring (or strut – some part connected to the knuckle). The spring acts like a stethoscope and you can feel the vibration when the bad bearing is spinning.
If you’re trying to find which joint to replace, don’t bother. It’s virtually never a good economic choice. While is is possible to replace just one joint, it costs the same as a new axle.
There are shops that specialize in CV axle repair that can get it done for around $100 to $130 or so, and they can do it quickly. My record for wheel off, to wheel back on is about 20 minutes, but not all cars are that cooperative. When you have to remove a starter as part of the process, things get more complicated!
As for bearings, sooner is better. If you think you hear them, it may be too late to avoid damage. Have them checked immediamente!
Is it cool to replace just one CV (or one bearing, or one strut for that matter)? I can totally see my grandpa whacking me in the back of the head, if he were alive, for not doing both sides while I’m under the car. He was a big proponent of “One side has failed, what makes you think the other is far behind?” I heard about it for years when I replaced a single headlight once. It didn’t help the second one died like 2 weeks later.
One CV joint (actually drive axle on one side, as ducati pointed out)? Wheel bearing on one side? Yes. For these parts, it’s often NOT the case that the other side will fail soon. Heck, some wheel bearings last the life of the car. And other than jacking up the vehicle, the work to do one side is totally separate from that to do the other side. There’s generally no reason to do them in pairs.
Struts are a different story. Usually both sides wear at about the same rate. Even if one is shot and the other is serviceable, that other one will be significantly weaker than the new replacement. Replacing just one can result in a disparity in shock absorber action (struts are almost always replaced because their shock absorber component is faulty) that could result in squirrely handling. It’s wise to replace struts (and shock absorbers) in pairs.
I used to drive Honda Civics, and in Canada’s cold weather, they wer notorious for failing, every year or two. Once the rubber cracks, dirt gets in and they wear quickly. you can try just replacing the boot rubber, but odds are by the time you find the crack the damage is done. OTOH, once it’s screwed, as long as it works, you’re Ok until it stops CV’ing; the trick is to replace it before it fails completely. Often i replaced the boot because the mechanic noted it was cracking, but as it had not failed, no need for a new CV joint.
A buddy long a go bought a Honda with about 40,000 miles on it and absolutely ZERO maintenance. When he changed the oil, it was like tar. The CV joints were bare, the rubber had cracked off a long time before.
I found that at tight turns a dying CV would give a clicking knocking sound.
Recommended - especially in cold (sub-freezing) weather, don’t park with the wheels cranked, you are stretching the rubber and encouraging it to crack.
Each CV is a separate item. It’s twice as much work to replace two, there’s no savings. Like replacing a faulty door latch or tire, just because one went, there’s no reason to believe the other is due. If the rubber boot is fine, it’s still Ok. If the rubber boot is cracked and open, then yes you will eventually replace that one too.