Output shaft oil seal leak

[28hodge]

Need your guidance please lads,

Splitting the cases from the bottom, who’s done it and what’s the trickiest bit?

Bike is fully back together following a total winter refresh of the engine, but sods law means that yesterday on its first trackday prior to Brands with Bemsee at the end of this month, it starts dribbling oil into the belly pan.

I quick check shows that it seems to be dribbling from the gear selector cover, Ok thinks I not a massive problem, I’ll smear some gasket sealant over it for the remainder of the day then get a fresh gasket for it. But the leak is getting worse with each session and I decide ill pack in at lunch head home get it stripped down and a gasket ordered.

Only to discover that it’s not leaking from here, it’s coming from the output oil shaft oil seal, dripping onto the gear selector cover and running around the gasket line so it appears to be leaking from there. Fan fuggin tastic!!

So I am going to have to split the cases to get it changed, not what I needed and not something I have done before. So anybody got some pointers or a guide that has done this before?

Think I may also swap back to the VFR gearbox as well at the same time, not a fan of the RVF box in my short usage yesterday!

[gavins]

It's not too difficult if you follow Mr. Haynes instructions. It can be done without removing the rear cylinder head, but access to two of the bolts is very difficult and only accessible by spanner. I'll tag you in a FB discussion on it from a while ago.

I've done it a couple of times but i've always chosen to remove the rear head to make life easier.

If you don't have a Haynes manual i can bring my copy in to work tommorrow and scan you the relevant pages, it does make life easier having a guide to follow.

It probably doesn't need saying but be sure to use a cardboard or similar template to keep track of what bolts go where.

[28hodge]

Thanks Gav,

Got a haynes but didnt think it told you how tp split the cases without taking the heads off first, but i didn't think to look either.

Managed to get myself sorted out and the engine is coming out of the bike this afternoon and is off down to the engine builders tomo and he is going to split the cases for me and swap my old NC30 box back into the engine. Although the 35 box may be better i found it a bit more difficult to select a gear with it, and also the oil seal thats gone back into the bike on the rebuild is the one that came with the nc35 box so thats why it is leaking.

Either way busy weekend for me as i want it all refit and up and running by sunday night!

[gavins]

I don't think the Haynes covers it specifically, you just skip the bit where it tells you to remove the cylinder heads and use a spanner on the awkward bolts instead of a socket. The rest is pretty well the same.

Hopefully it all goes to plan for you, i'll be at brands at the end of the month but helping out my brother in law rather than riding. Are you entering for snetterton in April?

[hunter]

If i was going to replace the seal,I would use a new one,
Just because it didn't leak before doesn't mean it won't leak when it's put together.

[28hodge]

So would I hunter but I can't get one in time so gonna have to swap my old one back in and hope. Engine needs to be back together and in the bike as of Sunday. I'm away next weekend and then brands the following weekend.

Yeah I'm at brands Gavin but not snetterton, girlfriend is Norwegian and her family are over to visit that weekend so it a no go.