Vintage BMW Motorcycle Owners

Does anyone know what would cause oil from leaking out the vent hole in the speedometer Trans breather bolt
Thanks

This info is available by a search on this thread, but the posted answer… by members far more knowledgeable than me, is that it is a way of relieving gear-oil pressure from a hot engine/transmission, thus avoiding seal damage.

Well, it's a little hard to add too much gear oil to the transmission unless you leaned the bike over on the right side to fill it. What is the oil you're running in the transmission? Could it be too thick and it's foaming up?

Thanks for reply
I'm running 80 90w

What year is your bike

Tommy

Too much oil in the trans may have this effect, have you checked the oil level in the trans?
It shouldn't be higher than the bottom of the filler plug's threads in the case.
Easy to overfill it if not adding via a premeasured amount, or the old oil had not totally drained before adding the new.
Also possible to have too much oil in the trans if the output shaft seal is bad, or was installed reversed, and so allowing driveshaft oil to drain into the trans.
Best-
George

Overfilled transmission or drive shaft would be a culprit with that.