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CV joints

what happens when cv joints fail, and how do I tell if they’re getting bad?

CV joints will make noise when they fail. It will sound like marbles rattling around in a tin can during turns. It may include pops and snaps, as well.

Worst case scenario? They bind, lock up, and send your car end over end on the highway. Naturally that’s when they’ve been wobbling for a good bit. Kinks …binds …noises when you’re making turns is a good indicator. You can also sense a slight wobble when starting out. It’s not like a universal going bad, more like having a tire that would be laterally challenged …side to side motion. They can do the slight side to side thing for an eternity and not require changing.

I recommend changing motor mounts when they’re serviced.

One really odd failure of a CV joint was one on the rear of a VW Bus. CV joints have what could be considered a inner and outer race. In the case I speak of I saw the balls of the CV joint (yes CV joints have balls) cut a groove logitudinaly around the outer race, this caused the inner race just to spin. When one axel of a VW Bus just spins, the Bus goes nowhere.

A bit of a flare for the dramatic there. I’ll tell you what, mjkelley - if you have a sudden CV joint failure that sends your car end over end on the highway, and if you live through it then buy a lottery ticket as soon as you can b/c you’re apparently on the thin side of the odds that day.

I’m not saying squirrely things can’t happen b/c they can, especially at high speed. But basically if the joint completely fails it cuts transfer of power from the engine/transmission to the wheels. So the most common thing that happens is that the car just won’t go. If you are driving it you will find that you can’t accelerate & will come to a stop. If you’re stopped you’ll remain so. The squirrely things can happen b/c there are multiple axles w/ 2 joints each.

They generally click, rattle, or knock depending on the severity and sometimes may only do this while cornering.

It’s also possible to have faulty CV joints that make no noise at all. They may cause vibration or lurching. This can be erratic in nature.
In some cases like this there is no way of knowing except by removing the halfshaft and physically going over it by hand to see if there is slop here and there or any hitches in the movement.

A bit of a flare for the dramatic there.

While I agree a failure of that nature may be rare, it’s not unheard of. Geeaea described it as a worst case scenario and I believe his description was fair.

I’ve seen CV joints break apart where the rotating axle whips around violently causing damage and eventually binding, causing the wheel to lock. I’ve never seen a car flip over from such a failure, but can imagine under the right situation, it could definitely happen.

I didn’t say it was impossible. I just said to buy a lottery ticket. Winning the lottery is also possible.