oil leak from prop hub

[xort]

My Tohatsu 9.8 has been sitting since October when I winterized it. I was looking at it today and noticed an oil leak from the inside of the prop hub. There was no puddle on the ground, just a streak of fresh oil on the bottom inside of the hub.

What's going on here?

Thanks

 

[Yepblaze]

Re: oil leak from prop hub

Quite often residual oils, and exhaust byproducts that had built up on the insides of the exhaust sections within the motor will drool out the bottom when stored.

Many times this is mistaken for an oil leak.

A simple test (if you know what gear oil smells like) is to smear some on your finger and smell it. If it smells like gear oil, investigate further.

 

[xort]

Re: oil leak from prop hub

It definitely smells like gear oil. Fresh oil. It was in a nice trail down to the edge of the hub. Probably a half teaspoon.
If I overfilled the case, would some seep out?

 

[robert graham]

Re: oil leak from prop hub

Remove prop and inspect for fishing line wrapped around prop shaft, under seal causing leak or seal damage. Clean area thoroughly, run motor while watching for leaks. Good Luck!

 

[ziton]

Re: oil leak from prop hub

My 30hp nissan was doing the same thing.
I drained the oil and noticed a little water.
Instead of installing a complete LU seal kit I went to the local
hydraulic repair shop and purchased new o-rings.
All three o-rings cost $5 and were very easy tio install.
No more leak
One o-ring was for the shift rod and 2 were for the prop shaft.
Napa did not have any of the o-rings.
A catapillar, heavy equipment or tractor repair shop should.

I'd check a hydraulic cylinder repair shop first.

 

[pvanv]

Re: oil leak from prop hub

Two types of leaks, neither one's good in the long run.

In one case, the lube leaks out. That's typically from the prop shaft seal. As was mentioned, unburned residue from the exhaust is frequently mistaken for a lube leak, especially on older 2-strokes. Also, it's common to get fishing line, etc., wrapped on the prop shaft, damaging the seal. If that's the case, you might get by with just the prop shaft seal.

In the other case, water leaks in, That's often at the driveshaft area. As was mentioned, one of the most overlooked seals is the shift rod o-rings. Check LU lube level. If it was severely overfilled, expansion could force some out. Since it's prudent to change LU lube at least annually anyway, drain the LU and see if there's any water contamination. If so, a re-seal is definitely called for. In that case, since the majority of the cost is in labor to drop and reinstall the LU, we usually recommend a full re-seal of all seals and o-rings.

 

[ziton]

Re: oil leak from prop hub

Wher can you get just the prop shaft seal online?

 

[pvanv]

Re: oil leak from prop hub

Any Tohatsu/Nissan dealer who sells online.

 

[xort]

Re: oil leak from prop hub

Pulled the hub...found lite fishing line.. I've gently unwrapped the fishing line from the shaft. I'll let it sit for the weekend to see if I have any more oil leak.

Thanks

 

[sea_goin_dude]

Re: oil leak from prop hub

If you have to old seal removed, take it to any industrial supply shop. They should be able to match the seal and or bearings with the numbers from the old ones. I have replaced many bearings/seals over years working industrial maintenance and years teaching maintenance for state adult ed.
And yes fishing line will cut seals out faster than you can remove them. Be sure to check everytime the boat or the drive is out of the water.

 

[sea_goin_dude]

Re: oil leak from prop hub

Probably replace the seal if you found fishing line. Best way to cut out a seal is to run with fishing line around the shaft.