Hole in the final reduction case - Is this normal?

[Yavuz]

My buddy bought an 86 Aero last year, and rode it a few times before putting it away. He ended up giving it to me yesterday and I've noticed a couple of issues with it.

Most of the issues are pretty straightforward and easy to repair but this has me stumped.

As soon as we moved the scooter from its resting spot - I noticed it was leaking oil from the transmission... thing is - there was no oil at all under where it had been sitting for 6 months.

The hole is pretty smooth - no jagged metal or anything... To me it looks like there might have been a plug or something there and it may have fallen out as we were moving it.

Here are the pics:





So... is this just a drain for the final reduction oil - or is this bike toast?

The bike started right up after a couple kicks and runs fine, I'd like to hang onto it if it isn't going to cost me a lot of money to repair.


Thanks a LOT!

-Yavuz

[Wheelman-111]

Greetings:

Your oil leak was unlikely to be from the transmission case, even though it appeared to be so. I would suspect a long-term pump leak - a few drops a month add up - or an oil feed line from the tank, or perhaps the fitting at the tank itself.

As for the square hole in the case?
It's normal.



Y'see, it is open to atmosphere but it is sealed off from the oil bathing the shaft bearings and countershaft gear. Dunno why, but that little hole comprises the totality of Honda-san's provisions for ventilating the belt clutch and variator. I guess it lets condensation out. Doesn't do much for cooling however.

If you pull the tranny cover off, you may need a new cover gasket. Honda-san can supply. The gear cover assembly as pictured is available for purchase in the lobby at the conclusion of this presentation. 11.097:1 gear reduction ratio, all assembled and ready to go.

[Yavuz]

Thanks for the quick response - I'll tear into it and see where the oil is coming from - On closer inspection the oil dripping out of that hole is the same color as the oil that's in the oil tank - so it's probably not from the case after all.

It's just weird that there was no oil under it at all but after moving it there was a ton of it pouring out of that hole.

[Wheelman-111]

Greetings:

The GN-2 is probably pooling in a dimple in the engine case somewhere. Waiting...

If your tranny's tired, I have the entire assembly.