Fork Seals and Bushings

Jakobi

Jakobi

Super Moderator
Yesterday I installed some new Race Tech fork bushings for a 2008 CRF450R. I also ordered a Motion Pro seal driver for the same model. These were to go into the 48mm Sachs forks.

Upon installation I realised the seal driver is for 46/47mm legs, and that the outer bushings slide up into the fork without the need to be driven. Basically finger tight only. All went together with SKF seals and wipers (the wipers are a super tight fit) and the fork action feels nice.

Just doing some post installation research and its hit me that the outer bushings are probably for a 47mm fork as well, and the inners too. In 2009 they changed to a 48mm and the part numbers for the bushings changed too.

Would you run these still, or would you pull the forks back down and change the bushings out? What risks are there? I noticed the outer bushing was a snug fit on the lower fork, and only finger tight in the upper forks which would make sense if its for a fork a mm smaller. It could possibly result in faster wearing of the dlc i guess. The previous bushings had heaps of play between the upper and lower legs, which has now been reduced significantly.

Thoughts??
 
Hi Jakobi!

Did you measure the bushings? When I did that same thing I bought H**da original parts from H**da shop. I had my old bushings with me and we measured them. I'm now not quite sure were they -08 or -09 models.

8 CASQUILLO FRICCION 52/48 L15 / BUSCHING DU 52/48 L15 BE200252509
9 CASQUILLO FRICCION 49/47 L20 / BUSCHING DU 49/47 L20 BE200302509

(Those are from GG parts fiche) H**da parts were exactly same. I don't have that Honda number anymore...


Being -09 might make sense because they used 48 KYB s that year.
 
I didn't measure them.. but from what you have said I've definately installed the smaller bushings.

Part numbers
Outer: FMBO 47152 (49/47 L15) or 47x15x2 (IDxHeightxThickness)
Inner: FMBI 47201 (47/46 L20) or 47x20x1 (ODxHeightxThickness)

For anyone looking to get the right parts they are:

Inner Fork Bushings (pair) FMBI 48201 P
Outer Fork Bushings (pair) FMBO 48152 P

Now my question remains. Where to from here? I don't really want to pull them back apart again if I don't have to. Mainly because the dust wipers are so tight it'll I'll probably end up damaging them on the way out. Which will mean more $$ on wipers, bushings, and more time down and out.

I had checked each fork leg through its stroke when they were off without the carts installed and they slide nice and smoothly. They still have a little play between the upper and lower fork legs as well. Once installed on the bike with the front wheel on they still slide very well and aren't binding at all.
 
Doing some more thinking.

The correct spec from a few different aftermarket supplies are 48x15x2 and 47x20x1

I have installed 47x15x2 and 47x20x1. Going over it in my head, and the logic might not be quite right. The smaller size should simply be a snugger fit on the lower fork leg, which will result in a slightly larger end gap. The issue could arise if the 47x15x2 was too tight as this slides on the fork and it could wear the coating off the fork leg however this doesn't appear to be happening as the lower fork slides freely without binding or scraping. The bushing was hard to slide on the fork leg if it wasn't lubricated, but with some oil it freely slid.

Does this logic make sense or am I making excuses?
 
Followed up my thoughts with a visual inspection. Lucky I did. Both inner and outer bushings seem to be taking the load on one edge predomidantly and showing wear after just an hours use. They've been pulled out and will be replaced by the 48mm ones listed above, along with fresh oil (contaminated from the wear).

I also noticed that one of the bushings on the TTX cart (one leg only) is showing wear while the other one isn't. This was noticed before putting the Race Tech bushings in so its not a result of that. Will get onto an Ohlins dealer to get that part.
 
GMP said:
Get that crap out of your fork and order the right parts! 47 does not equal 48.
Click to expand...

Thanks Glenn, You told me what my brain was telling me the whole time! Just took you longer than normal being preoccupied with your new toy :D

Synergy, are you saying that the SKF seals I bought will probably leak now that I've pulled them? I have already ordered the correct bushings for the job. Was hoping I'd be able to reuse the oil seals and wipers.
 
Been spinning wrenches at night not on the web screwing around and socializing with you guys.:D Seriously though, that might eat through your inner anodizing quickly if most of the load was over a small area, and it would be because the circumferance is different, and when forced around the larger tube would no longer be round.

You can't move a seal over the bushing land without a bullet tool, bag, or tape protecting it. If you clean and tape the land(only way for removal), grease the tape, it should be OK to remove.
 
Synergy-Seals said:
We have them.....worlds better than skf....and you can remove the seals then reinstall them over and over again.....if needed!
Click to expand...

Sorry for the hijack.

Will Synergy-Seals make bushing for 43 mm WP forks? I just installed Synergy seals and dust wipers, and for my next service, I need bushings. I'd like to get them from Synergy as I really liked the fork seals and wipers, and would like to support someone who supports this site.

Thanks.
 
blitz11 said:
Sorry for the hijack.

Will Synergy-Seals make bushing for 43 mm WP forks? I just installed Synergy seals and dust wipers, and for my next service, I need bushings. I'd like to get them from Synergy as I really liked the fork seals and wipers, and would like to support someone who supports this site.

Thanks.
Click to expand...

Not a popular size these days except for 85cc bikez.
I could make some at a later date but for now we will have to wait. I will post it when we do.
 
GMP said:
Been spinning wrenches at night not on the web screwing around and socializing with you guys.:D Seriously though, that might eat through your inner anodizing quickly if most of the load was over a small area, and it would be because the circumferance is different, and when forced around the larger tube would no longer be round.

You can't move a seal over the bushing land without a bullet tool, bag, or tape protecting it. If you clean and tape the land(only way for removal), grease the tape, it should be OK to remove.
Click to expand...

What you say makes perfect sense and the wear on the bushing also confirms it. Shouldn't have even bothered really. Another lesson learnt.

As for the seals, may be too late there too. The lower legs pulled right through on disassembly leaning the seals still just in the upper leg. Easily removed by hand. Visual inspection shows no damage but it may be too late. FWW I had one of the fork legs apart a couple times while going through the processes and it didn't leak. I guess its one of those things where its probably best that I just write them off as a lesson learnt too and go ahead and install new ones while I'm in there.

Anyone know if the 48mm KYB seals and wipers will work? I have a set coming with the bushings (purchased as a kit). Genuine parts. I may just compare sizes (properly with the verniers) and put the new ones in if they're the same, or gamble the skf if they're not.
 
Just to follow up this thread and bring it to and end. I purchased the full genuine KYB service kit. Both bushings, seals and wipers. Cost me $56USD which isn't a bad price at all for everything. They all fit perfectly into the Sachs 48mm legs.

I've saved the other SKF seals for a set of spares but they've been reemed in and out of the leg a few times so I don't know if they'll seal properly or not. Probably enough to save me in a bind, but not worth the effort right now to have them leak.

Just waiting on the Ohlins spring guide bushings to arrive. Probably info for another thread, but one side of one bushing in one leg only was flogged out completely. This was after intial pull down. I'm not sure if the leg had too much play which loaded the spring guide or not. My suspision was that the oil hole in the inner tube was not chamfered on the inner edge and as such ground the teflon off. I have used some wet and dry and cleaned these up from the outside so time will tell.

Really looking forward to getting the forks back on the bike and taking it out for a solid ride. She's spent too much time on the stand these last 2 months!
 
Jakobi said:
Just to follow up this thread and bring it to and end. I purchased the full genuine KYB service kit. Both bushings, seals and wipers. Cost me $56USD which isn't a bad price at all for everything. They all fit perfectly into the Sachs 48mm legs.
Click to expand...

What KYB model ? Or better yet, for what bike ?
 
Mine were listed for a Honda CRF450R 2009+ 48mm KYB (purchased through CRFsonly). I'm sure the same kit probably applies to next to all the YZF models also running the 48mm KYBs.

The bushings result in far less play between the upper and lower fork tubes as well. To be honest I'm really disappointed with the general finish of the Sachs forks. The spacer/washer that sits above the seal wasn't a very good fit or finish stock. The oil holes in the tube were too edgy internally. The stock bushings even though showing no wear had substantial play. Just seems like the fit and finish on them is pretty average.
 
Jakobi said:
Mine were listed for a Honda CRF450R 2009+ 48mm KYB (purchased through CRFsonly). I'm sure the same kit probably applies to next to all the YZF models also running the 48mm KYBs.

The bushings result in far less play between the upper and lower fork tubes as well. To be honest I'm really disappointed with the general finish of the Sachs forks. The spacer/washer that sits above the seal wasn't a very good fit or finish stock. The oil holes in the tube were too edgy internally. The stock bushings even though showing no wear had substantial play. Just seems like the fit and finish on them is pretty average.
Click to expand...

Does the fork rebuild kit for '09+ crf450r also fit the '11 gas gas 300 Sachs forks? I need to replace the seals in mine and might renew everything while I'm in there. Jakobi where is the best place to get these kits from? (I'm Sydney)

What else needs doing in there? You mention rough internal oil holes?

I'm also after heavier springs (I'm 105kg geared up) will the 48mm KYB Springs also fit? And can you recommend places to buy the springs?

Cheers
 
n_green said:
Does the fork rebuild kit for '09+ crf450r also fit the '11 gas gas 300 Sachs forks? I need to replace the seals in mine and might renew everything while I'm in there. Jakobi where is the best place to get these kits from? (I'm Sydney)

What else needs doing in there? You mention rough internal oil holes?

I'm also after heavier springs (I'm 105kg geared up) will the 48mm KYB Springs also fit? And can you recommend places to buy the springs?

Cheers
Click to expand...

Hey n_green. The 48mm Sachs are the same fork on both bikes so yes the KYB kit will fit. I purchased this one: http://www.crfsonly.com/catalog/product_info.php/cPath/24_129/products_id/3260 along with some other goodies to make postage worth while. Also got the 48mm motion pro seal driver. Bling tools.

You won't need to worry about the oil holes. The issues I had with them was due to going to an Ohlins TTX Cartridge which has a bushing which runs along the inside of the fork tubes. A rough oil hole then resulted in premature wear of the slide bushing. The stock OC cart doesn't have this setup so shouldn't cause an issue.

For springs I'm not sure either as when I went to TTX I dropped genuine Ohlins springs to suit the TTX. I could measure the stock springs for you as I have them in my spares box. Being from Sydney I would try Shock Treatment (racetech). They can probably supply all the parts you need.
 
Thanks Jakobi, will give them a call today.

Slightly off topic, do you know where I can get some fork bleeder valves?

Cheers
 
NFI. Take the small allen head bleeder screw out of the top of the fork and get the vernier calipers onto it. Measure up the thread and then ask racetech if they have any for that size. Odds are they don't because they are so so small! The other option is drilling and tapping the hole to take a bigger bleeder when you have the forks pulled down.
 
You must log in or register to reply here.

Similar threads

B
Replacement Fork Options for 2010 ec300
Replies
11
Views
83
(F5)
(F5)
V
GasGas GP300 KYB Fork Stiction Issue
Replies
5
Views
83
coopernicus
coopernicus
B
98 EC250 45mm Zoke oil seals?
Replies
3
Views
2K
webmaster
webmaster
J
2007 EC250 fork bush problem
Replies
7
Views
2K
JAD
J
M
Conventional fork upgrade
Replies
4
Views
3K
(F5)
(F5)
Back
Top