RC51 Forums banner

SP2 DIY Fork seal replacement

36K views 38 replies 12 participants last post by  kaz 
#1 ·
Figured I would post up a "how to" on the SP2 since the manual doesn't cover shit when it comes to the SP2 forks. This was my first set of fork seals I've ever done, so it was a learning experience for me. Figure I would pass on what I learned, hope it helps anyone looking into doing this on their own. If anyone has any suggestions on anything, I'd be glad to add it to the posts below.

A quick disclaimer: This is a fairly involved process, allow yourself the time to do it, and ensure you have everything you need before hand. Another thing to consider is that if you aren't 100% confident in doing this yourself, but want to give it a shot, have the money set aside to take it to a shop if you get stuck. It is better pay a professional if you aren't confident that you can do it yourself correctly. These are your forks after all, and are pretty damn important and expensive. Another note is that depending on what tools you have buy to get this done yourself, chances are very good that you will spend more to do it yourself the first time than a shop would charge you. My local shops quoted around $200-$280 for changing the fork seals and new fluid. If I would have bought the racetech spring compressor, I would have easily spent over $200 in tools on top of the other normal stuff I already had. The reason why I chose to spend more, is that the next time I need seals, I can do it myself for only the cost of parts/fluid. So I will be saving money the next time I do seals or refresh the fluid (which should be done yearly according to some). I also don't really like paying for things I can do myself, unless I don't have the time.



Tools needed:
Front and rear stands. The front stand needs to be the kind that lifts the bike by the underside of the triple clamp. Any way of raising the front will work, but the stand is the best option.

Wrenches and Sockets. You'll need a 32mm socket for the fork cap. A 19mm wrench, two 14mm wrenches, an 11mm wrench. And you'll also need whatever tools you need to remove the front wheel and forks. You'll need an Allen socket for the fork centering bolt (I'll have to look up the size) and one for the compression adjuster (same size as all the fairings, 5mm I think).

O-ring pick and a small flat head screwdriver.

Something to compress the fork spring while removing the cap. I used a ghetto-rigged solution that you'll see below due to not having the time to wait for the proper tools to come in the mail. I recommend at the very least getting something like this: Fork Spring Compressor Kit and using a ratchet strap like this: http://img.photobucket.com/albums/v304/tls-moose/funnies/01060001.jpg If you want to spend more money, the racetech spring compressor (I'll be buying one of these soon).

43mm Fork seal driver. I used the newer motion pro "ringer" style. Not sure if it works any better or worse than the normal kind. I think the other kind might be better as there are less parts and this one seemed kinda cheap and had sharp edges on the inside that required filing down. http://www.motionpro.com/motorcycle/tools/category/fork_seal_drivers/

A plastic bag. I used a zip-lock freezer bag to get the new seals over the threaded portion of the fork slider. I had bought one of the bullet things, but it wasn't long enough and didn't work that well.

A "fork oil level gauge". It is basically a big syringe with an aluminum tube on it. There are other ways of setting the fluid level, but this thing is dead nuts easy to use.

Damper rod holder tool. The motion pro one worked well, but did require slight filing/grinding to get it to sit all the way down in the cartridge. You can see that below also.

Torque wrench. 25 ft-lbs is what is needed for the fork cap and the centering bolt.

Random stuff: A bucket or something to catch all the old fluid when you need it. Clean rags, a couple cans of parts cleaner (I used non-clorinated brake cleaner), and of course new seals and new fluid (each fork uses about 500cc of fluid). A vise with soft jaws really made this much easier to do also.

Not 100% needed but made things a ton easier: a vise with soft jaws, and an impact wrench. I just have the Ryobi cordless lithium one, and I have to say I am very impressed with the thing. I am normally a dewalt or makita guy when it comes to power tools, but their stuff is getting more and more expensive, and the alternatives are much better than they were 10 years ago. I can do an entire set of wheels on and off my truck with zero issues. I don't think I'll ever be able to not have one of these in my toolbox again.

Hopefully these numbers are readable, don't forget fluid. I used the Honda SS-8, which is 10w oil.

 
See less See more
1
#2 ·
I backed out all my adjusters to full soft. I can't remember, but I think the manual says to do this too. Don't forget to write down where they all were at before backing them off.

First step after that is to loosen the "fork cap" which is the big blue nut on the top. It is a 32mm, same size as the rear axle. Do this before loosening the triple clamp bolts and do this on the bike. It will be pretty hard to do off the bike. Just loosen the bolt to hand tight, no need to remove it while on the bike.

The blue part is the fork cap (shown off the bike):



Next you remove the forks from the bike. The manual gives you the procedure for this. If you aren't comfortable pulling the forks off, I suggest you don't do seals yourself as pulling the wheel is rather easy and detailed in the manual.

(your results may look a little different)



With the forks off the bike, unscrew the cap all the way like so:



Empty the fluid out (not all will come out now, but empty what you can):

 
#3 ·
Next, remove the preload adjuster knob (it is the black nut). You do this by removing the small snap ring that holds it on with a flathead screwdriver. Here is the little ring shown:



Next you slide the white preload spacer down and pull up on the fork cap until you can cock the spacer over and keep the fork cap up. This will show the two holes in the preload spacer where the fork spring compressor hooks in. Here is my ghetto rigged spring compressor:



Compress the fork spring until you can get the 11mm wrench around the damping rod (below the 14mm locknut). Once this is done, you can get the 14mm wrench on the damper rod (above the 14mm locknut). Shown here with version 2 of the ghetto spring compressor:



With the 14mm wrench on the damper rod, use the 19mm wrench to remove the black 8 sided nut on the fork cap. Shown here after pulling the forks apart for clarity:



 
#4 ·
Once this is off, you can just pull up on the fork cap (the blue part) and it will slide right off the damper rod. With the cap off, the white preload spacer and black o-ring will come right off along with the spring. Once you do this, empty the fork oil again. You can also pump the damper rod in and out to get most of the fluid out.

Next, remove the dust seal with a small flathead or pick. Do it in small steps around the fork tube and you won't have to mangle the aluminum as it is very easy to scrape off the anodizing. The seals were pretty hard after 8+ years.



Then use a small flathead to pull the snap ring that keeps the fork seal in place:



After pulling down the snap ring and dust seal, it is time to pull the two halves of the fork apart. Do this by holding them in different hands and giving them a few good tugs to knock out the old seal and copper teflon coated slider bushing. You'll wind up with this on the fork slider and an empty fork tube:



Remember what order they are placed on the fork tube, as you'll need them in the same order when you replace them later.

Remove the top slider bushing with a small flathead by inserting it into the slit in the bushing and turning it. (if reusing these, be careful not to damage the Teflon coating). Then remove the rest of the old seals, snap ring etc. Don't spread the slider bushings too much if you need to reuse them, I just replaced them as I had new ones, but this isn't necessary unless they are worn.

 
#5 ·
Next, you remove the "centering bolt" which is the allen head bolt at the bottom of the fork:



I used a cordless impact, which is something everyone has right? If you don't you can use a second person and a ratchet and the damper rod holder tool:



My bolt didn't want to come out after loosening and removing the damper cartridge, so I removed the compression damping adjuster:



Here you can see the centering bolt. I used a small flathead to get the bolt out:



And here it is:

 
#38 ·
My bolt didn't want to come out after loosening and removing the damper cartridge, so I removed the compression damping adjuster:

The o-ring keeps the bolt from coming out and you can't get hold of it from the outside. What you can do is take a long wooden dowel or even an old wooden yardstick (whittle the end down) and tap it out from inside. It took very little force to bump it out and you won't have to take apart the adjuster.
 
#6 ·
With all the pieces apart, you can pull the needle out of the cartridge by loosening the 14mm locknut and removing the damper needle. This will allow you to get the rest of the fluid out of the cartridge. If you are going to cut down the top out spring, there are other threads that will give details on pulling the cartridge apart, but I didn't go that far.

After everything is cleaned up, they go back together in the opposite order. There is what the manual calls the "centering plate" that goes on the end of the damper cartridge. It looks like a bushing and can only fit onto the cartridge one way. Be sure and install it so it slips over the cartridge.



Here is the top of the cartridge, and the tool with modifications:





I found the easiest way to get the damper into the fork slider without the centering plate falling off the cartridge was to place the holder tool into the vise, then slide the damper onto it and the slider onto that:





Don't forget the new o-ring on the fork centering bolt, and to clean the threads of the bolt, and the inside of the fork. New o-ring part number:




Get out your ratchet and torque wrench and torque it down. After torquing it down, you can install the needle back into the cartridge and tighten down the locknut.

 
#7 ·
Next it is time to get the seals back on the slider:




If you read the manual, it mentions to remove the burrs from the slider bushings (the teflon coated copper bushings). I used some light duty sandpaper and they came right off.




Don't forget to put the larger bushing on first, then install this one:




Here is the bushing that goes onto the slider and how you press it into the fork tube with the fork seal driver (put the driver on behind the ring and use the ring to drive the bushing into the fork tube):






And here it is with the ring seated all the way down:

 
#8 ·
And here is the fork seal about to be driven. I highly recommend you lubricate the fork seal on the outside with some clean fork oil. The seal can be a pain to seat. Don't forget that if you put a lot of fluid around the seal, it will leak down the fork when you turn it upright. If you don't clean it up, it will sit between the fork seal and the dust seal, and you might think your seal is leaking again when it is just the left over fluid from lubing the seal during install.

Tip: If the ring clip is loose and getting in the way when installing the fork seals, slip it over the dust seal and keep it from rattling around your seal driver. It will go over it just fine.





Put the circle clip back in, and seat the dust seal (reused the old pictures):



 
#9 ·
Now it is time to fill the fork with fluid and get the level set. This is done before putting the spring or anything else back into the fork. Fill the fork up with about a quart of fluid:



Bleed the fork by taking the fork tube and sliding it up and down on the slider. Just be careful not to pull it up too far as it will puke fluid out the side of the slider where the holes are (yes, I did that). Also bleed the cartridge by pulling the damper rod up and down. The manual says to do each of these 8-10 times slowly, then let the fork sit upright for 5 minutes. Another time when a vise comes in handy.

Now it is time to set the fluid level to 135mm according to the manual:



 
#10 ·
Then you install the spring with the tapered end up. Do it slowly so you don't spill fluid everywhere. (never mind the first photo with the fork tube still removed):






New o-rings for the fork cap and damper rod (the first one is the o-ring that is missing in the picture, no the one that is at the top):








Then it is time to use the crappy spring compressor again and install the blue fork cap the same as when it was removed. Get the 11mm wrench to hold the damper rod up, put the 14mm wrench on there, and tighten the black eight sided nut with the 19mm wrench.



 
#12 · (Edited)
There was some discussion over seating the damper rod on speedzilla where this is also posted, so I'll put up a quote from SubSailor I found pertinent:



B Miller nice job, I was just gonna post asking if anyone has the SP2 fork supplement to the manual. One question:

If you're removing the rebound adjustment needle from the damper rod isn't there the usual deal with re-installing it to ensure correct adjustment, equal on both forks? The procedure on other Showa forks I've worked on is something like: screw the rebound adjuster fully out, then screw it in X no. of turns; thread the needle into the damper rod and screw it down by hand until it seats; back off the rebound adjuster slightly so you won't damage the needle tip when tightening the jam nut, tighten the jam nut.

Just asking, thanks again for the write-up.

JB
The manual doesn't say anything about pulling the rod/needle. I just put them back to where they were before, which was showing about two or three threads on the rod after tightening the jam nut (I can remember exactly as I did this a couple weeks ago before a trackday).
The owners manual shows the default OEM setting of the rebound adjuster is one turn CCW out from full in.

With that standard OEM setting, the two punch marks should align.



So what I do is turn the rebound adjust CW until it stops, then lightly thread the fork cap assembly onto the adjust case portion with my finger tips until the fork cap lightly (keyword) bottoms out and no longer rotates.



Then I tighten the jam nut, securing the fork cap onto the damper rod.

Then rotate the rebound adjuster one turn CCW and it should align with the punch marks, or pretty close.



I also found that tappet wrenches (which are thinner than standard wrenches) work far better at accessing the the thin hexes of the fork cap lock nut than standard wrenches.

I bought a pair of Snap-On tappet wrenches in 12x14mm (LTAM1214) and 17x19mm (LTAM1719), which work very well.



Snap-On does not give those wrenches away, so I suggest looking for less expensive alternatives.
 
#16 ·
Thanks for taking the time to do this b.miller! :)
 
#18 · (Edited)
Just to embellish a bit farther...
Here are some tools that will make the job easier.
They won't be cheap initially, but it's only a one-time purchase.
And you'll be everybody's buddy when they learn you have them (trust me). :)

Race Tech portable fork spring compressor, pn TFSC 01

This is worth the price when compressing fork spring spacers.
I usually mount it in the vice jaws, but hypothetically it can be used while the forks are on the bike (although probably not a sportbike with the upper cowl in place).

Race Tech shock spring compressor, pn TSSC 02

If you have to change shock springs to service the shock or dial-in your suspension, this is a god send.
Has different spacers to accommodate various brands shock retainers (Ohlins, Penske, etc.).
Plus has ends for clevis or eyelet type lower shock mounts.

Race Tech cartridge holding tool, pn TFCH 01 (Showa and KYB 20mm cartridges)

Holds the fork cartridge while loosening the cartridge bolt at the base of the fork.

Race Tech Pro Oil Level Tool, pn TFOL 02

I've been using the syringe with hose and level fitting like B.Miller used in his article, and mine never worked right from the start.
I'm guessing the seal swell agents in the oil worked their magic on the syringe plunger, so it took two hands and a lot of effort to hold and pull the syringe plunger.
Then the hose started falling off the tip, so I finally got pissed enough to spend the large bucks on the Race Tech unit.
The Race Tech unit (while expensive) is awesome!! I can see why they cost so much.
It's all CNC machined and oozes tech. Sorry, I just love my tools. :)

Race Tech graduated cylinder, pn TFCG 500

A 500 ml graduated cylinder for correctly measuring fork oil (used together with the oil level tool).

Race Tech aluminum vise jaws, pn MVJ 065

Used to hold fork tubes, fork legs, etc.
Aluminum is softer than steel to prevent scratching.

There are other tools, but I've found these are the core (well, maybe a bit more than core) of fork and shock tools.
 
#19 ·
Thanks guys. It was a bit of a pain remembering the steps for everything as I wrote the article a few weeks after doing the work.

Subsailor: I was really pissed at myself for passing up a good deal on one of those fork spring compressors from racetech. I always hate paying for stuff that I can make on my own (if I had a welder currently), and those are fairly simple so I talked myself out of it. I'll be keeping an eye out for another deal though.

I didn't have any issues with the oil level tool, but it was rather stiff to pull. If I pulled it too hard the fluid or air would seep past the seal. It was only about $30, so I wasn't expecting it to be a professional quality tool, but it did get the job done and I'll keep it around until it falls apart. That racetech one looks fucking tits.

I do have a set of soft jaws that I used. I think you can see them in the picture. They are just a cheap nylon or plastic set from jegs. They are actually the ones used for assembling an fittings. It was nice to have the multiple v grooves in them because I can clamp round stuff verticly or horizontally.

A shock spring compressor is next on my list of tools to buy, along with a no-mar tire changer if I am feeling frisky.
 
#20 ·
I understand doing the job on the cheap.
Necessity is the mother of invention.
I made my fork holder out of a 2x4. I actually use it more than the aluminum ones.

That syringe oil level tool should work fine, but the rubber tip on the plunger would get so tight that it would pull off when trying to extract fork oil.
It was a trick trying to hold the level tip into the fork while working both hands on the plunger, and then the hose started falling off the tip, and spewing oil all over the place.
I just got fed up and ponied up the bucks for the Race Tech unit.

BTW If you look at the tip, when you rotate the gold knob, it unlocks the graduated tip to the desired level, then locks it into place.
It's definitely not cheap, but it sure is trick.

I also completed my basic set of Ohlins fork tools as well.
So now I can do any work I need to on my FG832 forks.
And Ohlins tools are not cheap at all. Ohlins anything is not cheap.
 
#22 · (Edited)
Well, now that I am looking to do this job I am reviewing this excellent how to. Thank you for your efforts Brett.

This is probably a "one time" thing for me and I am trying to decide whether to do it myself by making what I need or sending the forks into the Honda dealer and letting them do it. There are no reputable shops around me so I would be forced to have them done at the dealer.

I spoke with the dealer and they advised they normally only replace the seal and gaskets. It certainly makes sense to me to replace all o-rings and such while everything is disasembled. I thought perhaps purchasing all parts via internet then sending them with the forks and telling them to replace all supplied parts, but I have a difficult time trusting a dealership. Between a rock and a hard place.

In my experience with dealerships; everything is half-ass. I got a feeling that they would only replace the seals and put the rest of the parts on the shelf. I highly doubt they would measure a correct amount of fluid either. I am guessing they would dump in a quart and call it a day. I really do not want to purchase any tools in order to do this job. Advice to those who have tackled it? Thanks
 
#25 ·
For a one time deal, if you don't trust your forks to a local shop, send them out to somewhere reputable. I'm lucky that I had a couple shops close by that I would trust to do the work if needed. If I didn't and I didn't want to do them myself, I'd rather drive a couple hours to a good shop.

Ask around a local riders, trackday, or racing forum. I'm sure somebody can reccomend a shop within driving distance. If it is far away, I'm sure you could make arrangements for them to be done while you wait. Just remember that this time of year, shops are busy.

You might also be able to find someone that is just a fellow rider with the correct tools and a thirst for alcoholic beverages.
 
#26 ·
I live 450 miles from the closest track lol. No real spotbike riders around here. All sportbike guys around here are running mid 90's or earlier 600's. I'm in middle of nowhere Maine. I am going to try and get the season out of it as it is a very subtle leak right now. If it gets worse I will be forced to get them done.

Seems like it is always something:banghead:

Sent from Motorcycle.com Free App
 
#29 ·
Yep, I've done the same before. You can also use a piece of camera film. Just be aware that you may have not pulled the piece of dirt out, but pushed it back into the fork fluid.

I'd say it is probably time to change the fluid out anyways (great time for new seals). Of course you can push it, but be aware that the piece of dirt may get back into the seal area.
 
#35 ·
That's the same one I used. I didn't really like it. I've never used the other simple two piece design ones, but it seems like they would be easier to use. The round ring that locks the two halves together kept rotating as I'd try to hold the thing on there. Of course whenever I let go of it was also when the ring just happened to be lined up. It also seemed like the tolerances are too big. The thing seemed a little loose when it was all together.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top