anyone know what would cause this??

so i turned my bike off and was clipping my helmet to it when i saw this on the rear gearbox. I didn't fill it through this cap--I filled it through the correct bolt about half-way up the height of the gearbox.

any ideas what would cause this?

 

Jdogg, I believe that is a 1-way breather valve for the case. Looks like you overfilled. I think there is a seal in that piece. looks like you blew it. Might have to buy another one. I may be off tho so may want to wait for more answers before jumping.

 

This is your rear end not a gear box,you have overfilled it and as it warms up the oil expands and leaks out the vent.

 

Yep, just a vent. Under the cap is a little hole. That's all. Too full or getting too hot (although you should smell too hot).

 

how can you overfill it?? You can't fill the oil higher than the filler hole on the side--it'll leak out. Is any other kind of oil/fluid/lubricant that could have leaked into that chamber through the drive shaft? I'm wondering if i have potentially much worse problems here.

 

what would cause too hot? I don't have a sense of smell--i couldn't smell it if it was too hot.

 

I'm sorry, but I have to ask the dumb question...

What weight gear oil did you put in the dif?

I hope is was 80W90.

If not, then you've got serious froth going on!

 

yup. SAE 80W-90

 

OY! What the heck is going on in that dif??

Man, I don't know????

Drain the dif, see how much oil is in there.

See if there is anything that shouldn't be.

 

I agree. I'd REPLACE the oil in the differential and then see what happens. If the oil that was in there was old or had moisture in it it would foam/froth and seep out the vent even if not overfilled.

If what comes out is really nasty I'd ride it a couple hundred miles and change it again.

 

It's possible the vent was plugged to start with. After the pressure built up in the differential, it may have popped the obstruction spraying oil out the vent tube as the pressure equalized.

 

hmm.. i guess that's possible. if it is frothy, and filled much higher than usual, is there anyway any other type of moisture/lube could have gotten in there?