E: Engine New oil leak after fitting Alton

[danno]

Hi
I've just finished fitting an Alton to my Rapide C and have a stream of oil coming from a primary chain case cover bolt. It's the one near the lower RH corner of the dynamo cover.
Appears to be dry above.
May be caused by pressure. Any help appreciated.

 

[danno]

Had a closer look and reckon I just need a new dynamo cover gasket.

 

[BigEd]

Had a closer look and reckon I just need a new dynamo cover gasket.

With a bit of luck that is all it will need.
The chaincase was designed to breathe out through the dynamo hole. I you make a good seal between the back of the generator and the case it will try to find another way out if it gets pressurised

 

[danno]

With a bit of luck that is all it will need.
The chaincase was designed to breathe out through the dynamo hole. I you make a good seal between the back of the generator and the case it will try to find another way out if it gets pressurised

Thanks. I pushed the Alton up against the case and tightened the clamp.
Maybe needs to be backed off a bit but wouldn’t want an oil leak there too. All seems oil tight around the Alton apart from the cover seep.

 

[BigEd]

Thanks. I pushed the Alton up against the case and tightened the clamp.
Maybe needs to be backed off a bit but wouldn’t want an oil leak there too. All seems oil tight around the Alton apart from the cover seep.

PD28 in the drawing below fits behind sprocket PD15/1. Oil droplets get flung off by centrifugal force allowing oil-free air to exit through the hole in the back of the primary case.

 

[danno]

PD28 in the drawing below fits behind sprocket PD15/1. Oil droplets get flung off by centrifugal force allowing oil-free air to exit through the hole in the back of the primary case.
View attachment 28933

Thanks, Yes, I see now. Forgot about the oil thrower.

 

[oexing]

Venting the primary via the dynamo does not appear to be an overly brilliant idea. So maybe you´d like to do as I did by drilling into the gearbox filler neck to use that existing vent ? That should hopefully keep oil inside .

Vic

 

[Robert Watson]

So now any oil blown out through your new vent will dribble and fill the gearbox. I generally run 80-90 in the gearbox and a straight grade (like 30wt) in the primary.

 

[Simon Dinsdale]

The gearbox vent is designed to allow the air in the gearbox to expand when it gets hot and vent and the pressure increases will be virtually nothing hence the small gearbox breather hole.
The primary pressure increase comes from the main engine past the main bearings and is more than just the air in the primary heating up and expanding. I think you will just do what Robert describes and blow oil into the gearbox as you have no oil / air seperator which is what the original oil thrower on the Dynamo drive tries to do.

The proper engineering solution is to stop the engine pressurising the primary and that can be done with an oil seal on the main shaft. My Rapide used to leak a bit of oil from the Dynamo area and fitting a proper mainshaft seal cured it.

 

[bmetcalf]

Touch wood, but my mains are seal-less and I have a closed cell foam gasket for the Alton, with no significant oil drips. (Hah, define "significant"!)