Cartridge Dissasembly

[APK]

Parts diagram show that my '97 Kayaba piston assembly should come apart with a 17 & 19mm wrench, it doesn't. Does anyone have any experience removing the nut on the bottom of the piston rod? Thanks in advance.

 

[marcusgunby]

I did a set of 97 kybs the other day-when we talk of the 17 and 19mm wrench we are talking of removing the fork caps.The nut you are discussing is the one that holds the rebound shim stack on the piston face? this is accessable after splitting the cartridge by heating it to break the threadlock agent.This nut is peened and those peens need to be ground off before you remove the nut.

 

[APK]

Where do I need to put the heat to get into it? Should I apply heat near the top of the cylinder- it looks like a wrench was intended to be used there (and maybe a screw driver through the holes at the bottom?

Also, once I get it apart, can I order new inner bushings? My local dealer says I have to order the entire assembly. I had an aluminum piece get crunched into 1000 pieces-many of which were lodged into the main bushings, and I'm guessing into the bushings inside the cylinder as well.

 

[marcusgunby]

Thats a tricky question-it really isnt something you should attempt without a good amount of help-you need to apply the heat to the top of the cartridge tube where it screws onto the top part.It takes a good amount of heat to break the threadlock, you can use a screwdriver through the holes at the bottom but be super carefull as the tube will distort easily.Once apart you will see the rebound/midvalve assembly and can assess the damage.You can buy the seals/bushes from any good suspension dealers(not main Yamaha dealers however).If bits have been floating about you may need entire cartridges.They are not cheap:(

 

[APK]

I think I will leave it alone and see how the forks work. I noticed very slight verticle wear marks on the rod- I guess from the seal at the top of the cartridge. Are there any symptoms that this can lead to (if the cartridge seals are in fact embedded with aluminum specks etc, and I keep riding them)? Is there risk of damage to any other part of the fork (or rider)?
Thanks-

 

[marcusgunby]

I would inspect as it could lock up solid if a bit is jammed between the cartridge and the piston.I would expect you could take the catridge assembly to your local suspension specialist and they dissassemble and inspect and advice.This is save alot of money as you have done most of the work.

 

[marcusgunby]

APK i need to apologise-i was mixing up the 97 fork with my 03 forks i did the same day.The 97 fork is very easy to disassemble-you do use a 19 and 17mm spanner to undo the bottoming cone (under the spring guide)it unscrews and then has a split wire that falls out as the 2 cones come apart(its easier than it sounds-just do it slowly)then the rod falls through the cartridge.Now you can see the midvalve and bushes/seals.

 

[APK]

A race tech video shows the same thing and on the parts diagram it looks like those pieces come apart with 2 wrenches- but mine do not. There is no flat surface for a wrench to grab. It looks to be 2 peices with the piece in the middle having 4 "notches". It definitely does not come apart with the 17 & 19 the video says it does. It may come apart- but I can't figure out how.

Do you recognize my description as being from another year? I bought the bike used so I guess anything is possible.

 

[marcusgunby]

It should have 2 flats on the cone-could they have been rounded off??It is possible it has something different fitted-can you get a digital photo of it??

 

[APK]

It hasn't been rounded off, it looks to be caught on some sort of lip (the lip cannot be seen, meaning the lip must be coming off the rod under the main piece). It's 2 pieces. The main piece extends above and below the outer ring. The outer ring floats on the main piece, and the main piece can move around the rod, but cannot be moved up or down. The outer ring is about the diameter of a quarter (this piece has 4 notches), and the main piece is not as big around, and a little greater than half an inch from top to bottom.

I'm going to try and get a pic for you, but I'm not too confident I can get it done. I appreciate your help, I hope I haven't confused you with the description above.

 

[KiwiBird]

Sounds like the 93/94 forks where the bottom out piston is peened on.

Is your damper rod 12mm, 12.5mm or 14 mm?

 

[APK]

12mm according to my trusty ruler. I'm hoping you will tell me if these are '97's.

 

[marcusgunby]

If you get a pic e mail it to me moggy105 at nildram.co.uk as you wont be able to put pics up until you subcribe(only $12)i will put the pic up for you.

 

[Jeff Howe]

what kind of bike are they from? KX used a peened on piston assembly. You can knock them off though and get a removeable assembly for them from Race Tech or C-Cycle I think.

 

[APK]

I took them to a suspension guy today. The cartridge is two pieces which are threaded and then peened together in 4 small circles near the top. I have to(very carefully) drill the 4 spots and the cartridge should come apart.

Worst case scenario is I screw it up, have to drop $130 on a new cartridge, and (worst of all) can't ride this weekend. But there is a good chance that small bits of aluminum are stuck inside and around the inner bushings- which would cause more probs later.

Thanks for your input on my problem

 

[marcusgunby]

Shocknut i should of asked what bike-i assumed it was a YZ but that didnt have any peens.

 

[APK]

Drilled the peens last night and the cartridge came apart no sweat. You know you have drilled far enough when the material coming out of the hole slightly changes color. It turns out that the inside was crystal clean, but I just had to be sure.