Replacing Fork Seals and Bushings

Blown Gen II fork seal. Got the innards out and inner/outer tube separated.

Question - what have you done to reseat the bushings for reassembly? I called GPS, Ben stated they built special tools to seat the mid and upper busing into the outer tube. What have you used?

Some pix..

The entire assembly. Each bushing is approximately located where it would be when assembled, fully compressed.



Close up of the bushings.



Here you can see where bushings 'bottom out' on the ridges. The 'middle' bushing sits about 4 - 5 inches deep from the seal, the 'upper' bushing sits just below the seal. Ben said the upper bushing can be driven in place by using the flat washer and normal seal driver + heat.



Another whole picture shot..



And finally, a little motobike juxtaposition at 38 degrees F.



Soo, for you do-it-yourselfer's, what have you used to seat these bushings?

PVC pipe?

Yamaha high dollar fixture part?

?????

As far as the damper rod holder goes, I found that if you just loosen the forkcap, then use a impact gun on the rod retaining bolt when the fork leg is inverted over a pan is all that is required. Then you can separate the tube and slider and dump out the oil. As for the bushing/seal driver, one of the premade units is hard to beat. Once bought, you'll have it whenever you need it then. Find them here:

https://www.motionpro.com/motorcycle/tools/...k_seal_drivers/

PVC Pipe worked out for me, just have to make sure the end is cut flat otherwise you will do considerable cussing

:jester:

RTSR1/FJR said:

As far as the damper rod holder goes, I found that if you just loosen the forkcap, then use a impact gun on the rod retaining bolt when the fork leg is inverted over a pan is all that is required. Then you can separate the tube and slider and dump out the oil. As for the bushing/seal driver, one of the premade units is hard to beat. Once bought, you'll have it whenever you need it then. Find them here:
https://www.motionpro.com/motorcycle/tools/...k_seal_drivers/

Click to expand...

I use the motion pro tools and I think they are well made, commensurate with the price point.

Sorry dcarver, I'm not answering your questions; but have a related question on the procedure. If nothing else this will at least bump your thread

Did you use the car jack method to pop the fork seal?

RTSR1/FJR said:

As far as the damper rod holder goes, I found that if you just loosen the forkcap, then use a impact gun on the rod retaining bolt when the fork leg is inverted over a pan is all that is required. Then you can separate the tube and slider and dump out the oil. As for the bushing/seal driver, one of the premade units is hard to beat. Once bought, you'll have it whenever you need it then. Find them here:
https://www.motionpro.com/motorcycle/tools/...k_seal_drivers/

Click to expand...

El Toro said:

RTSR1/FJR said:

As far as the damper rod holder goes, I found that if you just loosen the forkcap, then use a impact gun on the rod retaining bolt when the fork leg is inverted over a pan is all that is required. Then you can separate the tube and slider and dump out the oil. As for the bushing/seal driver, one of the premade units is hard to beat. Once bought, you'll have it whenever you need it then. Find them here:
https://www.motionpro.com/motorcycle/tools/...k_seal_drivers/

Click to expand...

I use the motion pro tools and I think they are well made, commensurate with the price point.

Click to expand...

For clarification, this tool will seat Gen II bushings? The 'middle bushing' sits approximately 4" deep in the outer tube, and is the difficult one I've been told to get seated correctly.

Sorry dcarver, I'm not answering your questions; but have a related question on the procedure. If nothing else this will at least bump your thread
Did you use the car jack method to pop the fork seal?

Click to expand...

No, I don't even know what that method is... I simply clamped the outer fork tube into a soft-jawed vice, applied heat to the outer fork tube using a propane torch (heat from outer fork tube lip down about 6 inches) until it was just too hot to touch by hand. Gently but firmly pull the inner tube out, using it as a slide hammer. Use multiple hits. Keep applying heat. I destroyed my bushings by not applying enough heat and popping the tubes with too much force, causing the middle bushing to destroy the lower bushing.

My first time, I'm still much better off $$$ wise than having a shop do it, and know I know better!

I probably shouldn't have posted since my experience is on other models. I have not had to take the forks apart on my FJR yet.

I have used the Motion Pro drivers on other bikes with good success. It does seem a shame to buy a tool for one job and then have it set a long time before another use.

I've got to admit that I hate rebuilding forks. Its one of the messiest jobs, especially if you're cleaning up after someone else who did not regularly change fork oil.

As for the damper rod, you might get it with an impact wrench.... and again, I have not done an FJR, but my experience has also required me to make tools for this job on some bikes, using very long socket extensions and customized end pieces to apply the holding force. Some of the universal holders have been useless in my experience, and I've tried to buy holders from Yamaha for a few bikes without success (admittedly they were old enough that the fact that Yamaha was no longer supporting special tools for them was no mark against Yamaha).

The Haynes manuals will sometimes give tips about making your own tools for various jobs like this. I prefer the factory manual in general, but sometimes Haynes has useful information about short cuts or custom tools.

El Toro said:

I probably shouldn't have posted since my experience is on other models. I have not had to take the forks apart on my FJR yet.
I have used the Motion Pro drivers on other bikes with good success. It does seem a shame to buy a tool for one job and then have it set a long time before another use.

I've got to admit that I hate rebuilding forks. Its one of the messiest jobs, especially if you're cleaning up after someone else who did not regularly change fork oil.

As for the damper rod, you might get it with an impact wrench.... and again, I have not done an FJR, but my experience has also required me to make tools for this job on some bikes, using very long socket extensions and customized end pieces to apply the holding force. Some of the universal holders have been useless in my experience, and I've tried to buy holders from Yamaha for a few bikes without success (admittedly they were old enough that the fact that Yamaha was no longer supporting special tools for them was no mark against Yamaha).

The Haynes manuals will sometimes give tips about making your own tools for various jobs like this. I prefer the factory manual in general, but sometimes Haynes has useful information about short cuts or custom tools.

Click to expand...

LOL on the job being messy. The Gen II's are different than any other fork I've rebuilt due to the 3 bushing arrangement. Getting the innards out (dampner, spring, valving, etc) was really easy. My tip is to leave the top cap on, keeping pressure on the assembly. Hit the 8 mm hex with an impact wrench and it's done.

I just might take some measurments then see if my bud can turn a special tool out of delrin or something..

dcarver said:

El Toro said:

I probably shouldn't have posted since my experience is on other models. I have not had to take the forks apart on my FJR yet.
I have used the Motion Pro drivers on other bikes with good success. It does seem a shame to buy a tool for one job and then have it set a long time before another use.

I've got to admit that I hate rebuilding forks. Its one of the messiest jobs, especially if you're cleaning up after someone else who did not regularly change fork oil.

As for the damper rod, you might get it with an impact wrench.... and again, I have not done an FJR, but my experience has also required me to make tools for this job on some bikes, using very long socket extensions and customized end pieces to apply the holding force. Some of the universal holders have been useless in my experience, and I've tried to buy holders from Yamaha for a few bikes without success (admittedly they were old enough that the fact that Yamaha was no longer supporting special tools for them was no mark against Yamaha).

The Haynes manuals will sometimes give tips about making your own tools for various jobs like this. I prefer the factory manual in general, but sometimes Haynes has useful information about short cuts or custom tools.

Click to expand...

LOL on the job being messy. The Gen II's are different than any other fork I've rebuilt due to the 3 bushing arrangement. Getting the innards out (dampner, spring, valving, etc) was really easy. My tip is to leave the top cap on, keeping pressure on the assembly. Hit the 8 mm hex with an impact wrench and it's done.

I just might take some measurments then see if my bud can turn a special tool out of delrin or something..

Click to expand...

I've not ran into that either yet. Haven't done an '06+. Might be able to slip some conduit (split it length wise for a tight fit) or something over the inner tube and drive it with the driver then. As for the Damper Rod, leave the Fork leg intact(spring and all), just crack loose the fork cap and then remove the bolt with a 1/2" air impact. They always come out for me. Not had one not yet. That being said, now I'll have a ***** of a time on the next! lol

Don ~

I've used a MotionPro driver when rebuilding the forks on my old Kawa Zephyr, and it did work very well. I think you are correct in your thought that it won't work for the lower bushing though, due to the larger diameter of the tool at the top preventing it from reaching the depth required.

Your idea of Delrin is good, another possible alternative would be a piece of brass tubing the correct diameter, turned-down if needed for an exact fit. PVC pipe has also served well in a pinch, again turned down on a lathe for appropriate fit.

The advantage of Delrin or PVC is that it will non-marring to the interior bore surface of the fork leg, an important consideration!

Let us know what works out for you.

Don

dsmack said:

Don ~I've used a MotionPro driver when rebuilding the forks on my old Kawa Zephyr, and it did work very well. I think you are correct in your thought that it won't work for the lower bushing though, due to the larger diameter of the tool at the top preventing it from reaching the depth required.

Your idea of Delrin is good, another possible alternative would be a piece of brass tubing the correct diameter, turned-down if needed for an exact fit. PVC pipe has also served well in a pinch, again turned down on a lathe for appropriate fit.

The advantage of Delrin or PVC is that it will non-marring to the interior bore surface of the fork leg, an important consideration!

Let us know what works out for you.

Don

Click to expand...

I think this is the road I'm about to travel. I took measurements of the inner tube OD, the middle bushing thickness, and the exact depth of the 'seat' point. I'll be searching the local hardware stores mananna looking for the cheap yet workable solution.

Honestly, I can't believe this hasn't been solved before... is this truly new ground?

Guess I'll post back to my own thread .

I've been to every hardware store in 4 counties looking for just the right size pipe. PVC, EMT, fence poles, plastic sewer pipe, electrical pieces n parts, blah blah blah. Looked like a goofball with my digital dial calipers measuring everything in site.

I tried 2" copper pipe, sawed in half. It's not deep enough to work effectively nor does it have an area to 'hit' in order to drive the bushing home.







Then yet another bright idea entered my cranium scareabellium.. What about a muffler shop? They can 'expand' muffer pipe using hydraulics... yeah, that's the ticket.

Only problems?

1. Muffler shop could only 'poof' pipe in ~2 inch sections. To drive the bushing home, I need a section about 13" long.

2. The fork tube at the tip flares out, which I didn't notice until I got home and attempted to slide the sleeves over the inner fork tube top.





In the meantime,

1. I'm still waiting on parts (bushings, seals, washer) from good ol' Gary McCoy

2. I have some hope in having a custom made bushing driver created by some talented folks who swore me to secrecy pending how well it works.

3. I found a local independent shop who said they would drive both bushings home for 1/2 shop rate, or 45 bucks. Since I want to get Crzy8 back on the road (it's been 2 weeks now), I may just spend the $$ on the shop then continue this quest for a good part. I sure wish I had my own lathe, I know how to operate them and this would be so over. Hmm, now I think of it, I wonder if they would sell me whatever driver they use?

Sooo, fellow Feejer pilots, any other ideas? Or do ya'll just pay the shop prices?

I paid the shop prices. For me..... it was worth the $100 to carry the forks to them @ 10 AM and pick them up that afternoon @ closing.

Your method is much more of an adventure and probably more fun. I just didn't have the time as I was leaving for Park City the following Saturday. :blink:

dcarver, i have a few machine tools and a little time so if you would like i could make you a tool simular to the motion pro but with a longer snout. it would clamp around the fork and you would have to provide a pipe to drive it down with. if it works you would have to do a write up and become custodian of the tool which would be a great honor. if your interested i would need a few dimensions and a couple of days.

on edit i dont come on here as often as in the summer so if you want a quicker response call me at (315)877-6820

just roy said:

dcarver, i have a few machine tools and a little time so if you would like i could make you a tool simular to the motion pro but with a longer snout. it would clamp around the fork and you would have to provide a pipe to drive it down with. if it works you would have to do a write up and become custodian of the tool which would be a great honor. if your interested i would need a few dimensions and a couple of days.
on edit i dont come on here as often as in the summer so if you want a quicker response call me at (315)877-6820

Click to expand...

WOW, what a great offer, and Thank You!

..and with that, here is the update. Dave from GPS machined out a 'sleeve' with just the right spec's to drive the middle bushing in place. It wasn't 'tall' enough to clear the inner tube top, so I found that 1.5" PVC pipe, on the bell end, fit perfectly. Then I found a 1.5" pvc broken pipe fixer upper thing that worked OK, but not perfect. I ended up gluing a bell-end to the broken pipe adapter thingie then stacking some more sawed off bell-ends on top of that to drive the bushing home.

Actually, the fork seal gave me more trouble...

Just Roy - If you can machine to pretty tight spec's, e.g. you have lathe with big enough bed, I will happily send to you the part GP Suspension sent me, or provide exact dimensions for you, and PAY you for the part - then offer it for free use to Forum members. Of course, if someone stiffs the forum and doesn't return the tool, the wrath of the Forum in the most massive dog pile ever seen will prevail..

Let me know if you are interested...

dcarver

dcarver, yes i'm still interested in helping out you and the forum anyway i can. my big lathe can spin 16" X 52" so i dont see a problem. e-mail me what you want and exact specs or give me a call and we can talk about it. my e-mail is [email protected]

just roy said:

dcarver, yes i'm still interested in helping out you and the forum anyway i can. my big lathe can spin 16" X 52" so i dont see a problem. e-mail me what you want and exact specs or give me a call and we can talk about it. my e-mail is [email protected]

Click to expand...

Damn! 16x52 is impressive. I will contact you tomorrow, and Thank You!

This is what this forum is all about - riders helping riders.. so Thanks Again for your contribution... :clapping:

The troublesome bushing (middle) is 48.05 mm i.d. x 53.0 mm o.d., when moderately compressed to close the split.

So any driver tool has to be a slip fit over the 48 mm inner tube. The o.d. has to be thin, I don't remember exactly HOW thin. I'll have to pull a fork to measure the chamber i.d.

A long driver tube is not the answer. A heavy steel collar at the upper end of a 8" sleeve will get the job done. The molded plastic dust shields on FJR forks makes the typical seal driver useless. It's a long way from the upper edge of the dust guard to the middle bushing.

I may be able to pull a fork and make measurements and drawings in a few days.

Ok, I measured the sleeve GPS made for me:

ID = 48.05 mm

OD - 51.05 mm

Wall thickness = 1.55 mm

Haulin', I was thinking, that for simplicity, if the sleeve was long enough to extend past the inner tube top, when the inner is fully inserted into the outer, the sleeve could be hit with rubber or brass mallet to directly drive the middle bushing into place. If the sleeve had a 'cap' then the cap would take the abuse of the hit and not distort the sleeve.

I'm not sure what would be easier to machine, a longer sleeve with PVC cap (or whatever)

or

your idea of an 8" sleeve with heavy metal ring, kind of like a non-sliding slide hammer.

I will say that it doesn't take much force to seat the bushing, especially if the outer tube is pre-heated to expand.

Whatcha think HA? You're more of mekanic than I am..

I'll cut and paste this as PM to Just Roy to see if he's still interested.