Hello, John Talley here with partzilla.com. Today we're going to spend a little bit of time and talk
about the wear characteristics then you're going to run into on a constant velocity clutch system.
Now these systems they all operate about the same, but they're going to look a little bit different
from manufacturer to manufacturer. But the parts that you want to study and look at to see if they
need to be replaced they're going to be pretty consistent across the board. Now the one we happen
to have on the table right now is off of a 2016 Polaris Ranger 900. So we've got the drive clutch,
then we've got the driven clutch or sheave, and then you've got the belt that goes in between
them. Now as they spin faster and they start to compress, that changes the gear ratio if you will,
going from the drive to the driven because it's changing the surface area that it's
riding on from the front to the back. Kind of think of it like a 10-speed bicycle with
a larger sprocket up front and the smaller one in the back, and as those ratios change
from the inside to the outside, so does your actual gear ratio.
But it is a constant fluid change-- hopefully-- as you go through the RPM
range. What we're going to do now is point out some of the physical attributes that
cause some of the riding conditions you may be experiencing. Some of those that would
indicate a worn system would be the machine kind of lurches when it takes off or you have
to give it an excessive amount of RPMs before it finally engages. Now once you
pull the cover off one, of the first things you want to get a good look at is the surface area
of the sheaves. Now if you can't get your eyeballs around there, your fingers will tell you a lot of
what's going on. Now what you're feeling for is to find any grooves or rough areas along the surface
all the way from the inside to the outside of the sheave, and you want to do this for both the
drive and the driven clutch. On this particular example, you can see and feel several grooves
toward the inside or further in of the sheave surface. Now was this clutch still usable? Yes,
but what I started to notice is a hesitation and a slight juddering when it was leaving off the line.
Now that I've seen it, it makes sense that the machine was operating like it was. Tight at the
beginning of your acceleration, that's where all the wear is, and that's where it was acting really
jerky as it was leaving off from a dead stop. Can you still get a little bit more mileage out
of this one? Yes you could, but with that rough surface area in there, guess what it's going to
wear against next? Your belt. Now you don't want it to be completely glass smooth, and we'll go
over that in a minute, but if it's as rough as this feels right now which almost feels like a
120 grit sandpaper? That's too much. Your belt is not going to last very long at all, and it's going
to make a big mess because it's basically acting like a sanding block, and then all that debris is
going to get spread throughout the actual case itself and wreak havoc on your weights, on your
bushings... I mean everything. So that is why I went ahead and replaced this one, because later on
it was going to cause a bigger problem throughout the entire CVT system. Now other than the surface
areas where the belt is actually running, you want to check the pivot points for both your weight and
your main carrier on the inside. Now of course this has a spring in it, and I doubt you'd be
able to compress it, but what you want to look for is to see if there's any side by side play
or if you can move that weight around a little too easily in here. Same thing for this. And you also
want to check the buttons on either side, and if they're completely worn out and you've got metal
on metal, well then you're done. Now if I were going to reuse this one-- which I wouldn't because
of the wear on the inside-- but if the inside looked good and I had this kind of play, I would
probably go ahead and at least replace the buttons on here because those are a replaceable item.
Now next let's take a peek at our driven or secondary clutch. Now I did bring in a brand
new one because I wanted you to see what the surface areas look like on a new sheave. Now the
secondary clutch as you can see is not nearly as complicated as the drive clutch or primary clutch.
But what you do want to look for of course is the condition of the surface area, but in particular
you want to look at these two rollers. Because these are the ones that are going to wear out in
the helix because it is constantly moving back and forth and these are going to wear down eventually.
Now the next thing I want to talk about is preparing them if you do have to replace
either your drive or your driven sheave or clutch system. I don't put them directly into the vehicle
straight out of the box. I think it's important to give this surface its best chance of mating
or breaking in the belt itself-- which also you should replace a belt at the same time you're
doing the sheaves. To do that you want to clean it up some type of contact cleaner along with either
a scotch brite pad or 1000 grit sandpaper. Either one, you don't want to get real carried away. You
just want to clean the surface off, that way it will get bedded in on your new drive belt.
Now if you're only replacing your belt, and both the drive and the driven clutch, they've passed
the visual inspection, you still want to go in with some contact cleaner and a Scotch Brite pad
and make sure the surfaces don't have any type of glaze. Because you want to rough
them up just a little bit, that way they have a better chance of bedding in on that new belt.
Next let's talk about the belt. You don't want to see any cracks
anywhere on the belt. The surface area that you want to study the most is this area right here,
on both sides. What you want to do is just run your fingers across and make sure that there's no
cups, because if you run up on a cup it's probably going to be the same thing on either side.
Now what causes that is either the front or the rear sheave is not turning,
and the one that is turning actually acts like a sander on that one area and eats into it.
When that happens, may-- you may not notice it at first, but over time when you go back to that same
area, it's going to get a little bit worse, and a little bit worse, a little bit worse. Before
you know it, you've got a big flat spot on your acceleration curve and/or the machine is acting
really jerky when it's leaving the line. Typically it means that you didn't have it in the correct
run-- either high or low-- depending on your conditions. Now east, where I am,
we run a lot of tight trails, and basically my rule of thumb is if you're under 20 miles an hour,
keep it in low. That's going to keep it further up into the sheave area or right in the sweet spot
where it's not torquing it so hard, if you're in a higher gear and it's having to work so much harder
to get things moving. So just keep it in the right gear. Well there you go guys. Giving you
a few things to look for when you're inspecting and/or replacing your belt on your CVT system.
Well listen, if you need any parts for your machine, why don't you come see us at
partzilla.com and we can get you taken care of. If you have any questions or comments, leave them in
the section below and we'll get them answered for you. We just want to say thank you for shopping
here with us at Partzilla, and we will see you in the next video. Y'all have a great day.