Clutch oil seal and sleeve gear bush

[Phil C]

Sorry, it's not very clear where the dribbles are. They're fairly thin dribbles and don't show up very well on the photo. I've wiped it now, because I smeared a bit of dyed gearbox oil on there in order to compare. (I don't think these dribbles are the dyed stuff from the gearbox.) But I can take the bike out again to produce more dribbles and take another photo. 

In the meantime, this old photo from about two years ago is interesting. Maybe I've fixed some of this, but I guess the present leak is quite likely to be coming from where some of this stuff two years ago was emanating.

I could revisit the alternator wires grommet idea, but the present leak appears to be a vertical run which it's hard to think has come from the grommet.

Phil.

[Mike40M]

"And I imagine you're running out of things to suggest?  Phil"
Not a chance, this is an internet forum. Stupid suggestions will never end. Especially during lock down, with nothing else to do.
It could be that the oil close to the leak is not yet contaminated by the dye. A long ride might show.
Had a bad leaking Burman gearbox. Solved it with filling it with the correct semifluid grease. Now almost oil tight.

[Phil C]

Here is something I posted a couple years ago:

I wonder if there's anyone there who has been following this. Anyway, here is an update, and of course a plea for help. Having replaced the oil seal behind the clutch, and the one at the gearbox sprocket, I have put everything back together, refitted the primary chaincase cover, and today took the bike for a run, just eight miles. The leak is much, much less, but I see looking under the bike that it is still there. Please see the attached photo, taken from the right hand side side of the bike, so the front of the bike is to the right of the gearbox drain plug. Any ideas please as to where the oil is coming from? (you might remember the leak only happens when the engine is run.)    Phil.

* IMG_20180827_145642.jpg (113.59 kB, 392x294 - viewed 84 times.)


I guess I improved it but didn't cure it. I might now do two things:  1. Go for a bit longer ride, and have a peep under the bike to see what colour the leak is,  and 2. depending on what I see, go back into the primary chaincase.      Phil.

[AWJDThumper]

Are you definitely sure the cover plate is not leaking?

[Phil C]

You mean the circular plate behind the clutch? No, I'm not atall sure.  Phil

[Phil C]

But I did give it a good clean etc when I was in the pc two years ago.

[Blackthou]

Re the cover plate, 2 things:

1 if you've drained the oil in the PC there shouldn't be anything to leak from there.

2. If there's residual oil in the seal it could just be the remnants seeping out.

I'd continue to potter around without oil in the PC, gently of course, to see if the leaks diminish and or stop.

[Phil C]

Hmmm, yes, thanks Rick, I might do that.  Phil

[morven21]

. . . and finaly, this is a British bike. They leak, period. Never seen one that didn't.  Years ago, in Bike magazine, someone wrote a list of dealer-speak phrases that were commonly heard by green bike buyers, an what they actually meant. My favourite was: " There are no real oil leaks, sir".  This was due to there being no real oil in the engine.  You have been warned, no leaks= no oil= sudden engine/gearbox death syndrome.

[DAVE BRADY]

Hi,

They all leak??  Back in 1996 at the German Summer Camp at Langeleben they didn't.  It was within a water catchment for drinking water so no oil could be dropped on the ground.  Every bike was provided with a drip tray.  All the drip trays stayed oil free except for the one under the old 'V' twin that had a total loss oil system.
I think I would say that they all could leak and probably have at some time, some do and many don't.   

Dave.

[morven21]

Interesting. I was talking of the late 60's, to mid 80's, when brit bikes were being ridden as dailies, not immaculately restored at 4k each models, with all their seals done. Breathers were directed at the rear chain, etc. I defy anyone to ride a Velo, AJS, BSA single hard across the continent an have it stay dry. As for Royal Oilfields. . .  But ok, it IS poss to have a dry bike, but you have to be very vigiliant.

[DAVE BRADY]

Hi,

Yes, back in the day when BSAs were daily and family transport they were more likely to have a leak as the they were kept on the road by owners who needed to do quick repairs over the weekend ready for Monday morning and despite their best efforts bits of damage would occur as many of them would have been reluctant mechanics.
Today with the luxury of better sealing materials and time to get things right it is possible to get an oil tight BSA without spending a fortune.  It is more about attention and care when assembling and then riding hard, within the design capabilities of the bike ,and long, within the design capabilities of the rider backside, is not a problem.
Even high mileage bikes an be oil tight.

Dave.
 

[morven21]

Aye, guess that's right. When i've got the M21 back on rd, i'll let you know. Cheers.

[Blackthou]

Personally, I don't think there's any excuse for an oil leak on an old bike anymore than a modern one. I agree that the bikes had chain lubes and breathers but they're not what I'd call oil leaks as it's intentional.

In 1972 I had an almost new A65 and it never leaked a drip.

Three years ago I bought a 1970 T120R and cured all the oil leaks on it. It still doesn't leak.

Last year I bought a T160 Trident and that is nearly leak free now - haven't finished yet.

This year I bought my C15 and have cured several oil leaks. She's nearly back together so look forward to continuing the quest.

[Phil C]

These are all very useful posts. They tell me that if my bike has a leak, well, it's not unusual (as Tom Jones might say) and there's no reason to feel down about it. But they also tell me that these leaks are not incurable, and that I could have a machine that doesn't drip oil. I'd love that.    Phil