VB chaincase oil leak

[MarkOgden]

Gents

One more request if I may. Took the bike on a spin in this glorious weather - very difficult to resist for sure. I took the opportunity beforehand to check the chaincase for oil - looked like hardly anything in there, dry-ish chain, and no drain plug to check for sure. Filled it with GP50 to well below the overflow hole - i.e. nothing came out from the overflow, and as I saw a spray mist of oil though the large inspection hole when the bike was running anyways, I bolted things up. Post run, I noted a weep of oil from the inside of the rear of the chaincase at around 2 o' clock. The nearside of the wheel was also coated in a film of oil. The chaincase joint looks sound. This was not happenning prior to my filling the chaincase.

Thoughts then

Where is the weep coming from? Difficult to see the rear of the inner chaincase, but I suspect the clutch/drive sprocket orifice.
Have I overfilled the chaincase? I consulted various manuals and it just says fill with enough oil so it escapes from the overflow. This seems too much. For the moment, I could fill it so it just touches the bottom of the chain. This is fine, but it is difficult to see the low point of the chain to judge.
Is there a drain plug for the chaincase? - bolted cast alloy halves by the by - not the pressed steel aberration! I can't see one - which is a bit odd, then again it may be me....

Many thanks

Mark

[roger.fellows]

Do you have a 'rear chain oiler' fitted to that, Mark?

On some models it is a small channel protruding from the back of the case. If so, it should have a tapered threaded pin with a spring fitted in the relevant case screw hole. Adjust as required.

[JohnnyBeckett]

hi i have got that chain oiler screw in my case i just screw it right in and just spray lobe the rear chain sometimes the chanel that the oil run down on the rear of the inner case gets damaged and the oil does not run on the rear chain

[nevhunter]

If the primary chain is picking up a bit of oil, shown by the fine spray when the engine is running, that's about all you can hope for. I close off the chain oiler and oil the rear chain occasionally with GOOD chain oil from a spray can applied generously and carefully, Get it on every link on the inside, after a run when all is warm with the bike on the rear stand. After a while I wipe off the excess from the rear chain and spray some chain oil through the large hole towards the cush drive with the motor idling.. This process has been my practice for ever(Almost). Having the lower chain guard OFF helps to get better access to the chain if it's really dirty. Nev

[MarkOgden]

Roger

I don't believe I have the rear chain oiler, but I will take another look to check. As I say, anything in that area is very difficult to see.

Nev

Yes, spray is evident. I have sucked out a bit of oil from the chaincase since and have lubed the primary chain with decent chain spray grease.

[JohnnyBeckett]

hi is the rear gearbox sprocket oil seal ok i don't think it is coming out of the inside of casing endless it well over full with oil and then it will leak out of the hole in bottom of the clutch cover

[MarkOgden]

Right then. It does appear that I have a rear chain oiler - well a sort of grooved spout coming from the inside of the inner chaincase which presumably dribbles oil on top of the drive chain below - see attached photo. Thank you Roger!

However, I cannot see any signs of a screw, just a small hole through the inner chaincase. I think this is the culprit, as oil seemed to be around that vicinity - since cleaned up - and I can see it flinging off onto the rear wheel. Not sure why that should be the case especially if the chaincase did not seem full of oil, but I think I will block up the hole regardless. I keep the the drive chain well lubed up manually in any case.

[alan.moore]

Mark
Here's a pic of the adjusting screw.

There is a 'trough' inside the case which collects oil 'flung' off the primary chain. This trough communicates, via a hole in the rear chain case, to the 'trough' in your photo. The tapered end of the adjusting screw alters how much oil comes through that hole. If you screw it right in it should block the hole.

Cheers
Alan

[MarkOgden]

Alan

Yes indeed - many thanks. However, this screw was screwed right in, so perhaps I am wrong in my assumption that it the oil feed spout that is causing the trouble. I cannot see much on the inner face of the inner half of the crankcase either. No obvious oil deposits. I think I'll just have to give it a run and take another look if I obtain an oily wheel again. As Johnny mentions, gearbox sprocket seal could be a factor. No idea if it is OK or not though....

[JohnnyBeckett]

hi the screw is a long one with a taper to a point some cases do not have a hole that go right through the inner case and just use a small screw in the outer case and the oiler for the rear chain comes off the oil tank