This instructional video is for dual chamber style forks.
Most modern Showa and Kayaba motocross forks are dual chamber style.
You can tell whether or not they are by looking at the fork cap.
The fork cap on a dual chamber style forks has two pieces, one for the outer fork chamber,
and one for inner chamber.
If your fork is not a dual chamber style fork refer to our cartridge fork seal replacement
video.
Hi, I'm Eric from Rocky Mountain ATV/MC.com, and today i'm going to show your how to change
the oil and fork seals on a modern dual chamber type fork.
To start off with we'll need a clean work area and clean rags, Tusk Cap Wrenches, Tusk
Seal Driver, Motion Pro Seal Bullet, Tusk Fork Seals, Race Tech Suspension Grease and
most importantly a Service Manual.
This is where the critical procedures and specs will be found.
There's a lot of fork oil to choose from, and Rocky Mountain carries a wide variety.
The first thing we're going to do is we're going to use our fork cap wrench, and we're
going to loosen the outer fork cap.
This is a lot easier to do if you do it while it's in the bike still.
Just go ahead and loosen the top pinch bolts on your triple clamp, and then break it loose
and then you can finish taking it off when it's off the bike.
We're going to slide the outer tube down a little bit and dump out the oil.
Go ahead and let that drain.
Get most of the oil out of the outer fork tube.
You'll notice that there's two holes on the inner cartridge, we want to make sure that
we get the oil out of those too.
We'll go ahead and rotate it around so those holes are down, let all the oil get out of
that inner cartridge also.
We're going to go ahead and temporarily install the outer fork cap.
Using soft jaws go ahead and install the lower fork in a vise using the axle boss or caliper
carrier.
In the center bolt back off the rebound adjuster all the way.
During assembly the center bolt will need to thread all the way onto the damping rod,
and having the rebound all the way out will allow this.
We're going to remove the center bolt from the lower fork leg.
Thread that out, it's going to remain attached to the damping rod.
Then we're going to take our fork cap wrench, we're going to grab the top of the fork and
push it through and slide that tool behind the center bolt lock nut.
Next we are going to remove the center bolt from the damper rod, we're going to go ahead
and back off the lock nut from it.
We'll remove that all the way off.
Inside is the push rod, we're going to go ahead and remove that carefully and lay it
down on our clean rag.
And then we're going to push back in on the top of the fork and remove our tool.
Let that rod back in carefully.
Now we're going to go ahead and remove the dust seal, just take a flat blade screwdriver,
very carefully slide that off.
There's an inner ring in there, once again very carefully not to scratch our inner fork
tube.
This seal retaining ring needs to come out or else the fork will not come apart.
We're going to go ahead and remove it from the vise, and we're going to remove the outer
fork cap.
Slide down the outer fork tube all the way.
We're going to carefully remove that inner cartridge and set it out on our clean rag.
There's going to be a little bit of oil coming out, just be careful.
There's also a spring guide in there that needs to come out.
Now, to get the spring out it's easiest to just dump it upside down, the rest of the
oil is going to come out along with the spring.
And lay that spring out on your clean rag also.
It's a good idea just to let the rest of the oil to get out of there.
Now, it's time to remove that seal.
We're going to slide it up, just kinda see where you're going to need to slide it to.
And go ahead and give it a couple firm pops, and the seal, and the inner bushings will
all come out.
Now we're going to go ahead and remove those bushings from the inner fork tube.
You kinda need to get your finger nails in there and spread it, it is a slit.
Sit all these parts out on your clean rag in order, and also take note of how they came
out, which side is facing up.
Slide the old seal off.
There's a little lip right there that you need to be really careful when we put the
new seal and new bushings back on.
Don't forget your dust seal and that inner retaining clip.
Now's a great time to refer to your service manual for fork part inspection to get ready
for assembly.
For assembly you need to start first with the seal bullet.
We're going to slide that onto end of the fork tube.
This protects the seals from the sharp edges.
Grease up the dust seal, slide that over.
You're going to need your retaining clip also, slide that down.
Now we're going to go ahead and install some quality fork seals.
We're going to grease them up real good so they slide down easy, have a good initial
seal.
Be careful of that sharp edge.
Go ahead and remove the seal bullet, then we're going to go ahead and put the washer
on, sits on your seal.
The outer bushing, it slide down also.
And then the inner bushing, and the inner bushing you might need to spread apart again
and slide into that groove.
Once all that's installed it's time for the outer tube.
You want to make sure that's nice and clean.
Slide that down, then we're going to go ahead and grab our Tusk Fork Seal Driver.
The first thing we're going to do is take that washer and that outer bushing and just
seat them.
We're going to lightly seat them in there and you can hear the driver bottom out a little
bit, kinda more of a metal to metal sound.
You'll be able to tell when it's seated.
We're still holding the upper fork tube at this point.
Now we need to actually slide, we're going to install that seal with the seal driver
again.
And the same deal, you're going to be able to hear that bottom out where it needs to
go.
It doesn't take a lot of force but it does take some.
Now it's time for your inner retaining clip, slide that in there.
And you can use your seal driver again, you can hear it click when it slides in.
Just a little tap and it will slide in.
Using your fingers seat that dust seal.
K, now we're done with the outer fork tube, we're going to concentrate on the inner cartridge
assembly.
That and final assembly will be addressed in Part 2.