Topic: oil in the gearbox cover

[_mark]

Hello. I fully rebuilt my engine (changing roller and journal bearings as well).
After 20 minutes of running engine on neutral on the stand, I found the area of gearbox cover with a quite big quantity of oil (let's say 300 ml or half pint for US readers).
Is this normal? I ask for this because in the past, prior to rebuild the engine , in such area there was much less oil...
If is wrong what could be reason? thanks

[PeWe]

The only thing I can think can give more oil is if the rubber end plug is missing in the oil transport to bearing cover.
It will pop and fly when using a water pressure washer cleaning the cases, outside as inside.

I have catched the plug and reinstalled.

If you want to sleep well, remove that bearing holder for a look. If missing, not good for gearbox where oil is transported.

See below where plug is in.

[Kevin D]

If it was dry it wouldn’t need a gasket on the cover or a seal on the shift shaft.
I can’t comment on your quantity of oil. I expect there is a passageway back to the sump.
There is a small o-ring on the bottom left of the bearing holder to keep oil flow to the trans shafts and clutch.
And as PeWe said a little rubber plug in the oil passageway from the pump to the bearing holder, I think it’s under the gasket.

I’m a little bit out of my pay grade here, I’m not an engine builder like many here. I have been inside of this cover just a couple times.

[BenelliSEI]

PeWe….. isn’t the rubber plug right there, under the gasket?

Kevin….. +1 to what you said.

[scottly]

There is supposed to be some oil under the cover. If you lean the bike to the side before removing the cover, less oil will run out.
The rubber plug is not necessary; neither my K1 or K7 motor have one. The gasket covers the hole, and the cover has an area that seals against the gasket.
 

[HondaMan]

This hole was open on the K0 engines, and shaped like a "D". In the K1 it received the little rubber plug (well, most of them from the Old Factory and almost all of the New Factory engines did) because the gasket weeped oil there from saturation with hot oil. The oil comes from the scavenge side of the pump, where it picks up hot crankcase oil. Part of this oil is sent here, and the rest back to the oil tank.

If the plug is missing and the gasket is well-sealed, it usually doesn't cause weeps. I've found, though, that if the oil gets real hot, like from 10w40 weight being used, and if the rubber plug is missing (or seriously shrunk from the years) it will again weep around this area, making a mess. I have sometimes gone to the trouble of drilling and tapping this hole shut with a real short, pointed screw (made from a 6mm screw, head cut off) to preserve the oil flow to the countershaft while also helping to seal it from a slightly-warped tranny cover.

[PeWe]

PeWe….. isn’t the rubber plug right there, under the gasket?

Kevin….. +1 to what you said.

Fully agree, John.
Only the o-ring as Kevin mentioned.
Again a good learning post whith good info.

I had no idea about no plug in early bikes.

[_mark]

Thanks everyone I will check for the rubber plug but I'm pretty sure is present.
3

[BenelliSEI]

Thanks everyone I will check for the rubber plug but I'm pretty sure is present.
3

If it’s there, put it back together and ride!

[MauiK3]

Yet another great little learning session here!

[enwri]

I maybe confusing this with another bike, but is there a brass ring in the end of the  transmission shaft that the nozzle on the bearing retainer has to go through?
I have a memory of having to slide one back towards the end of the shaft because the nozzle didn't go in far enough to ensure the oil didn't just flow back out. When the nozzle is in far enough the ring creates a dam that forces oil inwards along the shaft.

[HondaMan]

I maybe confusing this with another bike, but is there a brass ring in the end of the  transmission shaft that the nozzle on the bearing retainer has to go through?
I have a memory of having to slide one back towards the end of the shaft because the nozzle didn't go in far enough to ensure the oil didn't just flow back out. When the nozzle is in far enough the ring creates a dam that forces oil inwards along the shaft.

I don't recognize that as a 750 feature(?). The 750 tranny countershaft is pressure-fed from the scavenge side of the oil pump via this little port, which feeds oil to the center of the shaft via this [fancy] bearing retainer casting.

[enwri]

I maybe confusing this with another bike, but is there a brass ring in the end of the  transmission shaft that the nozzle on the bearing retainer has to go through?
I have a memory of having to slide one back towards the end of the shaft because the nozzle didn't go in far enough to ensure the oil didn't just flow back out. When the nozzle is in far enough the ring creates a dam that forces oil inwards along the shaft.

I don't recognize that as a 750 feature(?). The 750 tranny countershaft is pressure-fed from the scavenge side of the oil pump via this little port, which feeds oil to the center of the shaft via this [fancy] bearing retainer casting.

 Oh oh, it seems a lifetime of leaded fuel is taking its toll. "May the strongest affliction win."

OP, I got nothing more to add..


.

[_mark]

Hi. Today I re-opened the cover and I found where this oil is coming from.
There is a window that makes communication between gearbox and side cover. Such window is near the shaft of the pedal of the gear shifter
Is such window normal?

Please note that after I drained the oil the first time, subsequently and up to today other oil (approximately 3/4 liter, see picture)  built up without cranking or igniting the engine. So it seems a "static" leakage. Could it be the check valve of the oil tank ?

Thanks

[PeWe]

I had to check my 1975 block.
Same opening. 
I have never had a thought about it. The gear shifter with stuff need lubrication

[_mark]

Thanks PeWe.
Briefly resuming, is it correct that so much oil is going to flooding the lateral cover and that I'm too much overthinking about it ?
Consider that we are just above the oil pan.

thanks.

[PeWe]

The hole must be oil return

[denward17]

A look at the plug......

http://forums.sohc4.net/index.php/topic,191661.msg2231744.html#msg2231744