Fork oil seal direction?

[Donut 77]

Good afternoon. After a 2 month break I am back to resume the VTR.

As the old fork oil seals were more rust than seal, I have no good photo record of dismantling. Haynes drawing is not much help.

Two questions please:

Which way round does the oil seal go? My guess is that it’s spring down/towards the oil. This side is slightly fatter by 0.2mm. This would mean the writing is up, which most sources seem to advocate.

Secondly, the metal washer that goes under it, which way round for that too please. It’s much more rounded on one side. Again, my hunch is that the square side goes towards the oil seal and round side down towards the bushing?

Good to be back.

Can’t wait to get this thing running..

Cheers.

[AMCQ46]

Oil seal is springs down ( on the oily side) and writing up (on the Fresh air side).

Washer can go either way, the radius is just a side effect of the way it is manufactured, but I tend to put the square side towards the bush.

[Donut 77]

You’re a scholar. Thanks

For something so critical, I can never understand why the manual doesn’t give a bit of info beyond just saying ‘make sure it goes in the correct way’

[Donut 77]

Oil seal is springs down ( on the oily side) and writing up (on the Fresh air side).

Washer can go either way, the radius is just a side effect of the way it is manufactured, but I tend to put the square side towards the bush.

I’ve just put it all back together as you said, then found this in Haynes (see pic below)

I’m worried now that the washer IS meant to be radius side down/flat side up against the oil seal in order to work properly?

I was about to fill with oil. Really don’t want to pull it all apart and risk damaging the fresh seals. Could someone just confirm if the washer direction doesn’t matter please?!

It seems to be also known as a ‘back up ring’ and very specifically concave shaped in other forks, but always with the rounded side down.

Thanks!

[Donut 77]

Also, just found this on a CBR forum.

[sirch345]

I had a quick look at the Honda Shop Manual, but unless I missed it there doesn't seem to be any reference to which way up that washer goes. You can take a look for yourself from this link: viewtopic.php?f=31&t=18025

Only a guess, but Haynes may have put that bit in from their finds when they stripped down Firestorm forks when producing the Workshop Manual.

Out of interest which make of fork seals have you fitted

Chris.

[Donut 77]

Only a guess, but Haynes may have put that bit in from their finds when they stripped down Firestorm forks when producing the Workshop Manual.

Hi Chris, that was my suspicion too.. in the end I went with it the way it was. Seem to have worked just fine.

The ‘slinky glide’ from WeMoto…

Bike’s coming on nicely.. it’s wiring loom and carbs this week

[sirch345]

Also, just found this on a CBR forum.

It's a shame there isn't one like that for the Firestorm/Superhawk, that would have saved any confusion.

In your situation I would most likely do the same as you and leave things as they are now, as you pointed out to change it would mean damaging the new seals just to get them out, so new would be needed.

Thanks for the information on the Slinky Glide seals.

Good luck with the wiring loom and carbs this week

Chris.

[Donut 77]

Also, just found this on a CBR forum.

It's a shame there isn't one like that for the Firestorm/Superhawk, that would have saved any confusion.

I think they’re probably the same, if not then similar enough for the diagram to work across the two bikes..

I will no doubt be needing your help and others in the coming weeks..

TIA

[AMCQ46]

Don’t worry about it effecting the function of the forks, that washer is only there to aid disassembly. When you are taking them apart, after you have removed the clip above the seal, you use the upper fork leg as a slide hammer to get the seal out, and the washer is just there to ensure a good transfer of the impact force from the bush to the seal……it does nothing else.

[Donut 77]

Yes, I suppose there are no moving parts as such in that area during normal operation, so what you say makes sense.