Hello, John Talley here with Partzilla.com.
Today I'm going to show you how to rebuild the primary sheave on our 2007 Yamaha Grizzly
YFM700.
Not that tough to do, just need to get a couple of panels and that cover out of the way, we'll
go to the tool table, talk about the tools and the parts we're going to need, and then
we'll dive into it.
So let's go.
Welcome to the tool bench.
This is going to be a skill level two, but don't let it scare you off.
Let's go over some of the tools you're going to need to do this.
As always, a good 3/8ths inch ratchet, a couple of extensions, a good torque wrench, a 10
and a 12 wrench.
And on the socket side just a 10mm and a 22mm.
You also want to pick up a 4mm Allen.
On the special tools side, you're going to need a couple of 6mm bolts.
Beyond that you're going to need two different types of clutch holders.
They've got a basket-type holder, and then an outer holder.
So you're going to need both of those to pull this off.
Now, if you would, reference our exploded parts diagrams.
That's going to give you a very clear picture of how this is going to come apart, and more
importantly how it's going to go back together.
So, once you have your tools and your parts, we can go over to the machine and I can walk
you through it.
Not much to it to start with, guys.
just need to get this footwell out of the way.
It's just a 4mm Allen, and a 10mm wrench will do it.
Yeah, looks like this is looking a little rough.
It's got a couple of cracks in it, so I think I'm going to get another one of these ordered.
Next, I want to remove this upper panel so I can access the bolts that are holding on
the top of the cover.
Alright, let's remove all these 10mm bolts to get the cover off more easily, I'm going
to actually loosen up this brake cable so it'll have enough travel to go down and get
that cover off.
That should do.
There we go.
What I'm looking for here, this actual surface on the primary sheave up front.
I don't want to see any grooves in it.
The belt?
I want it to have a nice dull look.
I don't want it to be shiny.
Because if it's shiny, that means it's been slipping.
Some of the things that you want to be looking for that would have caused you to come in
here is you go to accelerate and the unit's real jerky or it just really doesn't engage
very quickly.
That's usually an indicator that you've got a problem with your primary or your secondary
sheaves.
Now we're going to go a little bit further.
We're going to pull off this bearing carrier.
Alright, let's go ahead and loosen up the secondary sheave just to make it easier to
deal with.
You do that with just a couple of extra 10mm bolts with a 6mm thread.
Want to make sure they're fairly long, when you run those in it's going to open the sheave
up, and what we're about to do here in a second is take off this large bolt at the end of
the primary sheave.
When we do that, it's actually just going to pull off and you'll see an inner bearing
and then the inner part of the sheave as well.
Alright, this is a 22mm.
Now, just that outer bolt, washer, and this whole assembly will come off.
This is the part we're concerned with.
This, we'll just leave it in place.
Looking at the sheave surface, it's actually in good shape on the inner.
The outer has a little bit of wear, you can see it, but I cannot feel it so it's good
to go.
So what we're going to do is take this over to the teardown bench, inspect our hub and
those sliders that it rides on, replace those if necessary, re-grease it, and put it back
together.
Alright, you'll notice that I've got an impact with a Phillips in it with a hammer because
I have found sometimes these can be a little tough to pop loose.
This one doesn't seem to be that bad.
But honestly, with an impact, isn't that so much simpler?
What happens, especially if you sink one of these and you get water and mud inside this
enclosure, well, it doesn't play well with the other moving parts.
It'll try to lurch forward or it doesn't want to engage at all.
Chances are, you need to open this up and take a peek inside because it's probably going
to be sludge in there.
I have opened them up before where it was like clay.
It took a lot of centrifugal force to actually break those weights loose, and that doesn't
make for very smooth acceleration.
Alright, when you remove this outer section, it should be an O-ring that you kind of have
to fight to get past.
But keep in mind that this metal isn't super think and you don't want to damage it prying
it off.
Just walking it around.
There we go.
There's that O-ring I was talking about, and all that grease that it's been packed with.
Like I said this one's in not that bad a shape.
That's about he consistency you're looking for.
But we're in here, we're going to go ahead and take it all the way apart, we're going
to clean it up, probably going to replace most of the moving parts inside.
So, let's go ahead and lift out that center section, see the sliders all the way around.
And then down inside this cavity you've got eight weights.
They make different weights depending on how you want the sheave to engage.
Now I've reordered a set but I just went back to the factory, but if you're looking for
a little bit of change in your acceleration curve?
That's when you start changing out your weights.
Alright, with all that removed, we're going to go over to the parts washer, get these
cleaned up, take a close look at them.
Very important that you get these really cleaned up well.
Because the last thing we want is any of that grease in the cleaning solution that I was
using to get over on the belt side.
Now, I'll be re-using the inner and outer sheaves.
If one or both of them are worn you'd want to replace them as a set.
Before you put it together, you want to get a scotch wipe pad and just rough up the surface
just a little bit.
We just want to knock off any type of smoothness so it'll bite into that new belt.
Like I said, this one looks good.
Usually if it's really worn out where these sliders are riding, you'll see grooves in
these outer protrusions that come out.
This one's in good shape.
The grease that you want to use for this, Yamalube makes it.
It's actually called ultramatic grease.
And in the manual, they say put 90 grams on each one of the weights.
But the way I do it is to put maybe an eighth to a quarter inch of grease on the weight
itself around the outer surface.
And that's always worked for me before.
Just drop them in.
They do not care which direction you put them in.
Alright, next let's coat down the surface where the sliders are going to ride.
Only four of those.
Since we're still making a mess, let's go on the inside of the sheave itself.
Now, let's lake the sliders, install them on the cam.
And we want the red side facing up.
Let's go ahead and put a little directly onto the sliders.
With all that together, let's go ahead and put our cam in place.
Let's get our O-ring, and it just goes to that first edge right there.
Just to make sure it makes it over, just a light just to the inside edge of the stopper.
Now let's push her back down.
Make sure we didn't pinch that O-ring anywhere and we're good.
Yeah that O-ring isn't trying to keep dirt out, it's trying to keep grease in.
Because when this thing's flying around, at the RPMs it's gong to be turning, it would
actually force grease out that edge and then make a big mess.
Not that I've ever seen that happen before.
Alright, let's get all of our Phillips back in.
Alright guys, let's go over and put it back together.
Alright, and that's definitely where it's supposed to be, because if it's sitting in
there flush, a little bit of the splines should be protruding out maybe an eighth of an inch.
And that's what we have.
Now, we tale that washer I was talking about, then put on our outer bolt.
Alright, at this point, we're going to get a holder to hold our primary and we're gonna
take it to 100 foot-pounds.
To have any chance of holding this still, I went up on top of the outer section of the
primary sheave and I'm just using a pry bar just to hold this still so I can put the 100
pounds on it.
There it is.
Now, let's get the out of the way, get the belt on.
While we're doing this, we want to make sure our arrows are going to the front, and they
are.
Bring it in and just walk it over.
Now, let's release those two tension bolts.
There we go.
Alright, that's as far out as she wants to go.
Let's get a little grease on the end of this shaft and then into the inside of the bearing
carrier.
Then we're going to get it bolted in place.
There are two dowels that are across from each other.
There's one to the top right and bottom left.
Make sure those are still either A, in the carrier, or on the machine itself.
And there are two different bolt lengths.
So the long ones go here and here.
These two are the short ones.
What's our magic torque number?
Seven.
Make sure our seal's still in there.
It is.
I don't see any cracks in it so I think we're good to go there.
All of these bolts are the same length.
Alright, cover's in place, let's go ahead and get the rear brake adjusted back to where
it needs to be.
Then we're down to just some plastics.
I went ahead and ordered a new footwell for it.
If you get a little bit confused, just reference back to our diagrams.
It's going to show you exactly how to get it back together and what goes where.
Alright guys, we've got all the plastics back in place, the only thing I need to do is refill
the oil.
We actually have a video on doing an oil change service on this machine, so if you need a
little help why don't you go reference that one.
Well alright guys, that wraps this project up.
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.
Have any questions or comments?
Leave them in the section below and I'll do my best to answer them.
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