videos

Go Back   VMaxForum.net > FAQ

Search FAQ Search FAQ
Search Word(s):
Matching Options:
Search in:

How To Disassemble The Front Forks
How to disassemble the front forks of a late-model Vmax

How to disassemble the front forks of a 1993-2003 (at least) model Vmax

Scott Greene

El Paso, TX

 

This minimal tutorial is to offer some tips for those who are having trouble getting the bottom Allen bolt out of the fork tube of a 1993-2003 (at least) Vmax, and do not have the damper retaining tool that Yamaha sells. In the process of installing Racetech constant-rate springs and Gold Valve Emulators, I ran into a real problem getting those bolts out, even with an impact wrench.

 

Sometime between 2003 and 2005, Yamaha appears to have changed the shape of the damper a second time. I have no idea how to help with those, but see the bottom of this page for a picture.

 

First, do you have a manual?  If not, it is available online (it?s big, 30 megs):

 

http://vmaxoutlaw.com/tech/VMX12-Service-Manual.pdf

 

In the manual, skip the ?supplemental? sections and open the service manual to chapter six (chassis) to subchapter ?front fork.?  It begins with a diagram of the tube assembly on page 266 of the PDF file.

 

I used the Clymer manual as well (the 1985-2003 one), and the chapter begins on p.366. Disassembly begins on p.371

 

A number of people have been able to remove the bottom Allen bolt of the fork tubes while the tubes are still on the triple tree. Eddie Ball recommends just relieving the tube air pressure and taking out the bottom Allen bolt while the springs, etc are still in place as these can serve to hold the damper still while you get the Allen bolt out. Have an oil pan ready because if you get the bolt out, the fluid will follow.

 

The consensus seems to be that attempting removal while forks are still in the triple tree, and the springs are still in (but you have let air pressure out), is your greatest chance of success. Use of an impact wrench here will give you a better chance, but you may need to make that piece (see below). If you are doubly unlucky (like me and a number of others), you will need to order the Yamaha damper rod holder (29mm, part # YM-33962 or 90890-01375) and T-handle (part # YM-01326 or 90890-01326) or attempt what worked for me below.

 

I first had to create an Allen wrench long enough to reach the bottom Allen bolts with an impact wrench, and found I couldn?t back them out. If you are lucky they will come out on their own. If you are not lucky, you will find that it?s turning but not backing out, because the damping rod inside is simply turning with it.  If so, you will need to remove the tube assembly from the triple tree and anchor it in a padded vise.  Then you need something to hold the damper rod from the inside so that you can remove the bottom Allen bolt.

 

The solution is a long rod or pipe with a slightly modified 1 ?? bolt head on the end that will seat well enough into the head of the damper rod to hold it as you remove the bottom Allen bolt.

 

I will break this into 4 stages:

1-securing the bike

2-attempting to remove the Allen bolts

3-(if needed) constructing a DIY damper retaining tool

4-miscillaneous hints, and emails I received

 

Step One ? Securing the bike

I bought a jack stand at Pep Boys for about $75, and cut some 2x4?s so that it would support the engine and not the exhaust.  I then tethered via nylon straps up to ceiling hooks and down onto the stand to stabilize it, as it could easily fall off of the stand otherwise.  I have hooks in the ceiling of my carport and in a work room, as I worked on the Vmax in both places at times.  I know from experience that a Vmax lying on your leg quickly gets uncomfortable.

 

 

 2-attempting to remove the Allen bolts

Oddly, the Clymer manual suggests leaving the front wheel axle in to hold the outer fork tubes as you remove the Allen bolts. As you can see below, the axle completely blocks access to the Allen bolts and must be removed. (Pic 1 ? view of the deeply recessed Allen bolt; Pic 2 ? same view with the axle in place, blocking access to the Allen bolt)

 

 


I cut down an L-shaped Allen bolt so that I could rig it into an impact wrench, but the Allen bolt spun without backing out. This happened with both fork tubes. Here I am holding the Allen wrench into the bolt with a pipe wrench

 

I recommend you give a go first at removing the Allen bolts with an impact wrench, if you have one. This is a minor project on its own as the standard Allen wrench fittings aren?t long enough. You can cut an L-shaped Allen wrench to get the long straight section of hexagonal rod (5/16 is equivalent to the 8mm needed) and fit one end of this into an impact socket, and it should reach deep enough to engage the Allen bolt.

 

At the bottom of this pic is a representative Allen wrench and above is the 5/16? one I cut down to fit into the impact apparatus. 8mm is equivalent. This allowed me to attempt to impact the bolt free, and if you are lucky this will work. If not, read on?

 

3-(if needed) constructing a DIY damper retaining tool

If they are stuck, you will need to remove the tubes now and place them in a padded vice and construct a damper rod retaining tool.

My problem was that I didn?t know the shape of the damper rod, and had trouble getting things to grab and hold it.  It?s really hard to see well by looking down the tube with a flashlight.  I crammed playdough down to take an imprint of the damper head. As you can see in the pics, the trick was to grind down the points on the bolt so it would seat deeply enough to grab. 

 

The head of the damper rod is shaped like a shallow 1.25 inch 12-point socket.

 

As you can see below, the Allen bolt actually threads into the end of the damper rod that is inside the fork slider; this is the Allen bolt placed into the end of the damper rod once out.

 

 

 

The below pic is of the damper rod, once out, and the bolt I fixed into the end of an iron pipe to hold it in place. It was a 1.25? bolt that I ground down until it grabbed into the damper rod. In my hand, I?m holding the damper rod upside-down.  The corners of the 1.25? bolt need to be ground down so that it will seat deeply enough for the ?flats? to mate against the damper rod.

 

 

After I got the damper rod out, I also found that a brass quick-disconnect coupling (see below, pic 1 - it fits snugly into a 1.25 inch socket and pic 2 - into the damping rod) would have worked as well.  If you can locate one of similar shape, it?s a pretty good fit with less work than the bolt head above required.  It was part of a garden hose quick-disconnect set.

 

 

 

Once you have something long enough to hold the damper in place, you can remove the bottom Allen bolt, and this required firm pressure on the retaining tool with one arm as I impacted out the Allen bolt on the other end.

 

4-miscillaneous hints

  • I did find it necessary to heat the slider around the oil seal for removal. This will heat-expand the slider. The Clymer manual recommends rags soaked in hot water and warns against direct flame. I used a hair dryer.

 

  • Protect all sliding surfaces from your DIY tool. This can be done by finding large nylon or rubber washers or pieces of PVC that will act as spacers to keep the bolt/rod centered as you drop it down the tube.

 

  • Don?t forget to lodge something behind the brake lever (see below), because if the wheel is off and you depress that accidentally, it will take some extra work to get the rotor to slide back in between the brake pads.

 

  • Replacing the seals is a lot like replacing bearing races.  You need something of the same diameter that you can use to tap them into place without damaging them.  I used the old seals topped with a corresponding diameter of PVC pipe and a rubber mallet to do so.

 

  • You need to use the tool again when putting things back together to obtain the proper torque on the Allen bolt. The Clymer manual recommends loctite as well.

 

  • After replacing the specified fluid, checking the level is done by cycling the tubes fully in and out a few times without the springs in, to distribute the fluid through the damper, etc. You then check the level with them fully compressed, such as you would check a car?s oil via a dipstick, and measure the airspace from the top of the tube to the level of the fluid. This space should be 123mm (4.84?) on 1993-on models.

 

  • Sometimes, small seal leaks will cure themselves after a little bit of use, but be careful because those drops can end up on your front rotor (tip courtesy of Jim Greene).

 

  • Oddly, I don?t recall why I needed to do this, but I found it necessary to restrict the movement of the steering head and I did so by placing the knurled end of a socket wrench into the steering block.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  • The following picture was sent to me by Trent (VMOA #4060), and it is of the head of a damper from a 2005 Vmax. It almost looks like somebody is hell-bent on making us purchase a damper retaining tool, as I have no idea how you can hold that with anything! He was able to get one fork tube apart by removing the Allen bolt while the fork was still together, but on the second fork the damper just spun. He was able to cut down an Allen wrench to fit into an impact socket (see above) and was successful with the second fork tube.

 

Thanks to all who helped with this page (Mike Costa, Vmax Outlaw, JMB, Trent, Eddie Ball) and please send any tips or criticisms to sgreene at elp dot rr dot com.

 

The following email was from JMB, aka Gangway, of the Vmaxtech list. If I had thought of using my Jeep to hold the damper holder, I would have done so, and he makes it all sound easy:

 

I tackled the problem differently and have done so several times without any

trouble at all.Drain the fork oil.

Loosen the top clamps of the steering head ( 3 trees) or you won't be able

to remove the capscrews to take out springs.

Drop the fork legs out. The damper holding tool is a 24mm nut or bolt ( 29mm

for post '93 bikes with 43mm dia forks) welded to a 80cm long 12mm dia piece

of construction rebar (rod) with 20 cm or so bent over to form an"L" bar.

Make sure the nut or bolt has bevelled edges, if not, get out the file.

Locate the tool in the damper socket, lay the whole thing on the garage

floor and push your car wheel over the "L" to hold the tool, shove the long

end of the 8mm Allen key into the bolt head, use a ring spanner on the short

end for leverage and bingo.

JMB

 

 




All times are GMT -4. The time now is 12:49 AM.

Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

MorleyMuscle.com Exactrep
top of page