Does rolling ball sound mean cv boot is leaking, cv joint is faulty or other?

Question

I currently have one inner and outer cv boot linking on the same axle(or driveshaft - not sure what the correct terms is). Mechanic looked and it and told me it hasn't progressed too far to damage the joint and so all I needed to do was change the cv boots.

I forgot to mention to him that I also have a rolling ball sound(like marble rolling in a box) under the car which comes over uneven roads and maybe when taking turns. Having googled it, seems some suggest this rolling ball sound is commonly due to a damaged cv joint. If so this would mean there's no point repairing the boots as I'll have to change the joints so in order to avoid two consecutive repairs I may as well repair the whole axle anyway.

Can the described noise come when the cv boots are leaking or does it only come when the joints have become faulty and will need replacing? If the visual inspection suggest the boots only need replacing should I do that only as the mechanic advised, or since the sound is there should I change the whole axle instead? It could also be that the the ball sound is due a third issue but the inspection only reveals an inner and outer leaking cv boot at the moment.

Thanks.

Answer 1

If the CVJ is making noise, it's on the way out. They typically will make a clicking noise when taking corners when in bad shape or going out. They will usually only make the clicking noise in one direction (either left/right turn), but can happen in both directions. You won't hear the inner joint, as it's the angle of the extreme angle of the joint which causes the steel balls to deflect within the joint and make the noise.

You can "just" replace the boot as long as there isn't any noise and the grease hasn't escaped its trappings. Usually what happens with the joints is, the boot splits and spills the grease, then dirt/road grime enter into the area which should be sealed. This causes wear on the joint and then the noise starts.

You could possibly clean out the joint when changing the boot, then regrease it completely, to have it sealed back up with a new boot. This might get your car down the road a bit further. In reality, though, once it starts making noise, the joint is on the way out and you're going to end up replacing it soon anyway. As you state, it doesn't make much sense to do the job twice. If it's already making noise, you have to see the writing on the wall.

You can change out just the joint on many axles. It usually isn't too difficult, but realistically, with the aftermarket parts today being what they are, it's usually easier and not much more expensive to just change out the whole drive axle with new joints then it is to change out a single joint. Sometimes you have to weigh what your time is worth when getting parts. I had an '86 Prelude which I changed out a single (outside) joint. It took me three hours to figure out how to get the joint past the circlip which held the joint in place. I finally got mad at it and slammed the end vertically on the ground, which the joint popped right over it. If I'd just gotten a complete axle with new joints, it would have saved me a huge amount of time (yah, this was before YouTube and the internet, lol!).

Answer 2

A rolling noise can be a wheel bearing going bad. It's near the CV joint, but not directly involved.

Does it only happen when the car is moving and increase in volume as you accelerate? Does it change when you turn the steering wheel or stay the same?

A test is to raise each wheel (safely) and spin it by hand. You should hear the bearing noise on whichever wheel is having problems. There could be more than one bad bearing.