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Countershaft oil seal - b@stard thing!

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Looks like RC45 part has no lip, but not available. I usually get this kind of stuff from here: https://www.mcmaster.com/shaft-seals/ . Appears SKF #15922 will work.



To help in difficult install cases like these, I usually grind 45-degree bevel on back of seal and use seal-driver to push it in. Gently hammering on exact centre really keeps it from rocking and going in crooked. Perhaps you can cut section of PVC tubing to clear output-shaft and use seal-driver?




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Thanks for clarifying the part numbers Dangeruss - I missed the detail.  

Good shout on the bevel, Danno. I was going to use a Stanley blade to cut off the lip. Do you recommend a better way? How did you grind yours? 

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I use edge of angle-grinder disc. Clamp grinder in vice and angle seal just right and rotate through fingers. Practice on old seals.


Although in this case, slicing off lip-only with knife is better as you don't cut through rubber-layer entirely, causing it to peel off when installed. And piston-ring compressor is genius idea!!! 🙂Using some Hondabond as lube would probably help.

One thing to do is examine wear-groove created by previous seal on output-shaft. Then install new one slightly outwards or inwards from previous position so it doesn't touch at same groove.


EDIT: you can get straight-edged ones if cutting off lip didn't work.











There's options available such as double seals and alternate materials like viton for harsh chemicals. This isn't demanding application with high-RPMs, or high-pressure or high-heat, so I suppose basic NBR would be perfectly fine.

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Many thanks for all this info guys.


Over the past year I have been bringing my '95 gen4 back to life after 10 years laid up.


Last Friday it went 4 miles to its MOT test. It passed the test. Then came 4 miles back.


On Saturday morning I had a small puddle of oil underneath that I traced to the output shaft seal. I had previously changed the shifter shaft seal for the same problem.


After reading this thread I now plan to shave down the lip on my replacement seal using the smooth wheel on a bench grinder to put a bevel on the edge at the same time.


All the alternative seals already have these bevels, but they wouldn't be needed if you are expected to drop it into a split case.


Whilst the side of the bike is apart I'm going to replace the rest of the rubber components in the area at the same time.


I expect to replace the clutch slave cylinder seal and the clutch pushrod seal. Have I missed anything?


All my parts are on order, they will turn up eventually. I think I know what to do, except for one thing...



If I pull that clutch push-rod out to remove the seal, will the rod be easy to get it back in again? Or should I work around it to replace its seal?

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15 minutes ago, SEdwards said:


If I pull that clutch push-rod out to remove the seal, will the rod be easy to get it back in again? Or should I work around it to replace its seal?

No problem removing the clutch pushrod, you might want to put a compressible sleeve on it to reduce the rust and consequent damage to the seal ... the rubber boots from brake calliper slide pins work a treat filled with grease 

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Today I trial fitted a new Honda seal inside out (with the lip facing outwards) just to test the compressive fit. 

Well it’s tight but does go in. 

If all else fails I’m guessing the seal could be installed inside out with the lip cut off and some 3 bond, no? Is there a reason it should be fitted one way rather than the other? 

It shouldn’t come to that as the seal will slide in nicely with the lip removed but I’m curious. I’m fact it might even be good to leave the lip on to give the 3bond something to hold into? 

EDIT: scratch the backwards seal idea. Pressure forces would be acting the wrong way and not pushing the outer lip against the bore. Seal should go in right way round. Thank you YouTube university! 

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Thanks everybody for your input - your contributions have helped get this seal installed! 

Firstly, forget the piston ring compressor. Seal has a metal body so it can’t compress at all (no matter how hard I cranked)! Also, the compressor isn’t remotely slim enough to squeeze into the bore with the seal clamped inside it. 

I trimmed off the seal’s lip with a Stanley knife at 45* to leave a slight chamfer. This will make it easier to start the pushing. 



Next, a bit of 3 bond on the OUTSIDE of the seal and a bit of grease on the INSIDE hole. The 3 bond doubles as lube to help the seal slide in the bore. 


Easiest to just grease the shaft so the seal picks it up as you slide it over. Tricky to handle the seal with adhesive on the outside and lubricant in the inside! 


Then find a nice fitting cup/glass/bottle to drive the seal home by pushing against the outer edges. 



If you’re using the wife’s favourite juice bottle and you crack the bottom with a hammer, best get your excuses ready beforehand! 

Seal was driven home about 0.5mm deeper than the old one to avoid any grooves already formed. You can see a tiny sliver of the 3 bond poking out from the sides. 



Then I slathered a bunch of 3 bond over the outer mating surface to give it the best chance of holding fast. It’s ugly but will be completely hidden from view so if it works I’m happy! 



Careful not to get any on the sprocket cover/cage thingy gasket surfaces though...


We will find out how good this is when I eventually fire it up in a couple months or so. 

Some advice: if you’re doing this forget about cutting the lip off an OEM seal and just buy an aftermarket one without a lip. The cut seal’s edge kept wanting to roll off the metal frame as it squeezed into the hole. An aftermarket one would be more solid and unlikely to peel. 

Thanks again for your help and good luck to anyone else having a go! 

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Glad you got this sorted.  That looks really good.  Please give us a long term update after you've gotten some riding in.



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