'80 9.9 Johnny Prop Shaft Seal Leak

[Kev]

My motor has developed a small (a few drops a week) oil leak from behind the prop, I'm assuming from the prop shaft seals.

Should I just top off the lower unit oil periodically, or is this leak something I must immediately fix?

If it should be fixed immediately, do I need any special tools (bearing puller, etc) to replace the prop shaft seal(s), and how many seals are there?

I've misplaced the link to the BRP parts # diagrams so if anyone can help me out with that, it would be much appreciated!

Thanks in advance,
Kev

 

[wilde1j]

Re: '80 9.9 Johnny Prop Shaft Seal Leak

Drain the oil, look at oil for water. Test the lower unit [empty] with pressure [< 15 psig] and vacuum. Should hold prerssure/vacuum for ~ 45 minutes, some leakdown is OK. If there's a leak, submerge in water to find it.

Link:
http://epc.brp.com/default.aspx?brands=ej&lang=E

 

[Walker]

Re: '80 9.9 Johnny Prop Shaft Seal Leak

Are you sure its not unburned oil from the exhaust housing. That's the most common oil drip from the hub. Smell it and tell us what it smells like. L/U grease will have a nasty sulfur smell.

 

[Kev]

Re: '80 9.9 Johnny Prop Shaft Seal Leak

wilde1j: Thanks for the link and the advice. It doesn't look like I have any water in my L/U oil. Normal dark brown/light black color, not milky. Very "oily" feeling.

Walker: I'm pretty sure the oil is lower unit oil. It smells strong, the same as fresh L/U oil in the tube. I'm used to a bit of unburnt oil dripping from the back side of the prop by the plastic ring, but this is a new drip that seems to come from inside the lower unit in front of the prop, and then drip very slowly down the back of the skeg. Only a few drops a week. Is this anything to be concerned about?

Thanks for the help!
Kev

 

[Walker]

Re: '80 9.9 Johnny Prop Shaft Seal Leak

If it L/U grease and its leaking out then water is leaking in. Drain it and see what the old grease looks like.

 

[Kev]

Re: '80 9.9 Johnny Prop Shaft Seal Leak

Drained it, and it looks normal to me. Dark brown color, not milky, very oily feeling. No sign of water that I could see.

Is it possible my leak is so small as to be inconsequential for now?

Kev

 

[Walker]

Re: '80 9.9 Johnny Prop Shaft Seal Leak

I'd refill it and run it a trip or 2 and then check it again.

 

[Kev]

Re: '80 9.9 Johnny Prop Shaft Seal Leak

Cool, thanks! That's exactly what I was thinking to do. Before I drained it, I noticed my oil level was not at all low. I tried to top it off with an oil squirt can of L/U oil and it was down half a squirt or less. So maybe my leak is super small.

Thanks for the advice, Walker!

Kev