Hey, friends.
It's Len here from 1A Auto.
Today, we've got a vehicle in the shop and we've got a bad CV axle boot.
We wanna show you what can happen with that and a couple possibilities of how it can happen.
With that said, let's get right into it.
Well, if you're looking down underneath your vehicle and you happen to see a whole bunch
of grease just spraying all over the place, more than likely it's because one of your
CV boots is torn open.
Maybe you were doing some work on your vehicle and you happen to nick the boot in some way.
Ah.
Maybe you're heating something up and you melt it a little bit.
Oh geez.
Oh man.
There's lots of possibilities that could cause an axle boot to split open like this.
Is it dangerous to drive?
Well, maybe you could drive around for a little bit like this, but it's gonna of course make
a mess.
And then of course it's gonna accumulate dirt, debris, and even water inside there.
And it's gonna cause an issue with the CV joint.
I wanna show you what's going on inside the CV joint so you can see what I'm talking about,
but I did wanna show you the mess that could potentially occur as this is spinning around.
Okay, friends, so 1A was nice enough to give us an axle so we can tear it apart and show
you what's going on on the inside.
Let's just do a brief overview of what's going on on the outside.
If you were to look down at this end, this is the portion that's gonna go inside of your
transmission.
Sometimes this part isn't necessarily gonna be as long, you might have an area that just
kind of ends right about here and this is gonna slide into the transmission, or otherwise
you might have this shaft that's in the transmission already and it might just slide into the female
portion of the axle.
So there are a couple different axles that you may or may not have.
With that said, we're gonna move along.
This part's gonna be the closest area to the transmission.
If you were to come right along here, this is the inner CV joint.
And it has to be able to move around freely because as you turn your wheel, this one right
here is gonna want to turn and then of course, this is gonna sway a little bit.
Of course, you're gonna have your intermediate shaft that's in between the two joints right
here.
And then if you were to go past the outer joint, you're going to see this splined area
right here.
The splined areas where it's gonna go right inside the wheel bearing.
And then of course you'd have your nut that holds it together.
So if you were to look at the clamps on these boots, you're gonna notice that they're special
clamps.
If for some reason your clamp was broken or it came off for any reason and your boot could
shift, you'd probably wanna replace the clamp, right?
This is definitely not something that you want to use on an axle joint.
I'm sure you can understand the reason for that without me having to say, but this area
right up along here has a little bit of weight to it.
And as this axle is spinning around whether you're going 20 miles an hour or 60 miles
an hour, or maybe you're a speed racer and I'm not gonna say how fast you're going, but
this is spinning, spinning, spinning, right?
And so if you have weight that's just kind of spinning, it's gonna obviously throw off
the balance of the axle and you're gonna feel a shake more than likely in the steering wheel.
So it's also super important to talk about the boots on these CV joints.
If the boots are torn, worn, cracked, or anything like that where dirt and debris or even moisture
can get inside, it's gonna cause major issues.
So let's take a look at what's going on inside these CV joints so we can see how that would
cause an effect.
Okay, so we took off the axle boots for you so you could have a more clear view of what's
going on inside these axles.
You're gonna notice that the outer joint is much different than the inner joint.
The outer joint is more complex.
It has six ball joints inside of it or little ball bearings and the inner ones actually
gonna have three bearings inside.
And the bearings themselves are much different.
Let's go ahead and pull this apart.
If you were to look at the bearings that are on the inner portion, you're gonna see all
these little needle bearings.
They come right along here, okay.
That's the actual bearing.
And then this metal part rides right on top of it.
Of course, those bearings need to have grease inside of them.
And that's gonna help with friction and everything and heat dissipation.
So that's great.
If you had a torn boot, there's potential that dirt and debris could be making its way
inside here and working its way inside of these bearings right here, which of course
is gonna cause an issue.
It's gonna bind these up.
And of course, if there's moisture, it's gonna end up seizing these up over time.
Now, if you were to follow the shaft out towards the output aspect of the axle, you're going
to see a much different looking joint.
This is actually a CV joint right here.
It has six little ball bearings inside of it and they run inside grooves that go along
the outer housing.
And then of course, they go along this portion right here.
This center area right there is just the race and that just kind of holds the ball bearings
from moving around.
They're supposed to move around like this, in and out of the grooves, but this protects
them from kind of just falling out and going inside the boot and doing whatever they want.
Kind of keeps them controlled.
Once again, if the boot that was supposed to be covering this, let moisture or debris
inside, you can imagine what dirt or rocks or anything else is going to do inside this.
You need to have this be a nice smooth machine surface.
Now CV joint axles are super important, especially for front-wheel drive vehicles.
The reason for that is because that's where the power is gonna be coming out of the transmission,
going directly to the axle.
And it's gonna have to of course, push those wheels, which is going to move your vehicle
down the road.
If your vehicle was just going in a straight line all the time, you wouldn't necessarily
need to have a joint like this.
But if you're driving in normal circumstances where you have to maybe go left or right,
or veer or whatever you have to do, you need that joint to be able to bend.
In extreme cases, maybe you're doing a U-turn or turning inside a parking lot, trying to
park, you're gonna have that axle turned quite a bit.
If you had a regular U-joint in this like maybe something that was in a truck, what
you would probably notice is it would start to bind if it was this turned.
With this joint being this way, I can turn this.
It doesn't matter, I can turn, turn, turn, and it's not going to have any issues.
This is gonna be just fine.
I can drive all day around and around in a circle.
As long as there's plenty of lubricant in here, there won't be any issue.
If there was a U-joint, you're going to have issues.
So obviously this isn't an axle.
This is a steering shaft, but it does have a U-joint on there.
And it gives me a good way of showing you what's going on.
If you have your constant velocity joint, I can have this turn completely and it'll
still turn just like this, no binding, no resistance at all.
If I was to turn this as far as it would wanna go, which of course would be super far, we'll
say about that far, about the same distance as this, as I try to turn it, it's going to
bind and then loosen up and then bind and then loosen up.
Obviously that's gonna cause a major issue.
If you're just going in a straight line or even just turning a little bit, you're really
not gonna have as much of an issue.
And with U-joints like this, there's minimal area to contain the grease.
So you're probably gonna have binding issues like this.
I don't know if you can hear that.
Turns easy this way, not so much this way.
So now if you were doing front end work on your vehicle, maybe you took off that upper
ball joint and you happen to pull your knuckle away, some people might tell you to be super
careful because you might separate your axle.
Well, what does that mean?
Imagine that there's a boot on this right here, so you can't tell that there's a joint.
Now, if I was to pull down on my control arm on my knuckle, I should say, and pull it away,
that's gonna pull this outer portion out and it's gonna separate like that.
Okay?
You wouldn't be able to see this because it's going to be inside that rubber boot.
Well, now you need to try to put this back together.
So now with the boot on there, you have to try to imagine where everything lines up and
kind of feel around.
And then you're going to have to try to give it a push, push, push, push, and more than
likely, it's gonna have a lot of trouble going in.
That's because of the way that these are right here.
Now, if these are pushed in the inward position, you're not gonna be able to get this into
the outer portion, right?
So what you would have to do is just try to separate all three of them, put them so they're
on their outer most aspect and then it should just slide right in, which of course would
be very difficult to do if it was covered in grease and of course a boot over the top.
So it's super important if you know, you're doing front end work and you're going to be
pulling that knuckle away from the car and you might separate the axle, just go ahead
and loosen up that axle nut right down on this end, push this through a little bit so
it's coming through from the wheel bearing, that's gonna give you a little bit more slack
and then that way there, when you're doing the front end work and you're all done, if
you happen to pull the axle out this far, it's really not that big of a deal.
It'll just slide back in.
If you happen to pull it out too far, like I said before, this part is stuck inside the
car or truck, whatever you're dealing with and then you try to put this back in, it's
going to be really difficult to do.
I mean, you can kind of move it around usually and you'll probably be able to get it in,
but it's going to be very hard.
It's much easier just to make sure that you don't actually separate the axle in the first
place.
Now, if you happen to notice that you have a rip boot and you've determined that there
isn't very much contamination, you can try to replace just that boot and of course the
corresponding clamps.
But for me, time is money.
That's gonna take probably a lot of time and a lot of work.
I would just go on down to 1aauto.com and I would order myself a new one.
Okay, friends, we had a lot of fun making this video.
Hopefully you learned a little something along the way.
If you got something to say, leave it in the comment section below.
While you're at it, if you like the video, why don't you smash on that like button for
me?
Would mean everything to me.
And of course, subscribe and ring the bell that way there you can be kept up with all
of our latest content.
Thanks.
Mark: Thanks for watching.
Visit 1aauto.com for quality auto parts shipped to your door, the place for DIY auto repair.
And if you enjoy this video, please click the subscribe button.