small gear oil leak

hutche

Seaman Apprentice
Joined
Dec 19, 2010
Messages
36
hi all just curious of a small gear case leak on my 1978 115 hp johnson serial 115 etz 78c 632032.its only a small leak but would this require new gear case seals?if so what part numbers am i looking at ?im going to drop the oil and see if any water has worked its way in which i doubt.the other question is if its not taking on water could i just keep topping it up untill our so called australian summer ends and then give it a seal change if needed?thanks for the advicePhoto0262.jpg
 

1946Zephyr

Vice Admiral
Joined
Oct 21, 2008
Messages
5,556
Re: small gear oil leak

Well, the first thing I would do, is like you said, check the gear oil. If it still looks like oil, instead of milkshake, then you're fine. That would only mean that your oil that you're seeing is from the top end. If you do decide to change your oil, replace the washers on your drain plugs.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: small gear oil leak

Agree with Zephyr but if you find water in it have it pressure & vacuum checked to find out where the prob is before you tear it appart.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: small gear oil leak

I just caught your pic and to me it it looks like unburned fuel/oil from your p/h. But ckeck your lower unit for sure.
 

Vic.S

Rear Admiral
Joined
May 4, 2004
Messages
4,719
Re: small gear oil leak

As above . It looks like partly burnt oil from the fuel.
If it smells burnt or of gasoline then that's what it is.

If it has the viscosity of gear oil and smells like gear oil then you probably have a prop shaft seal leaking, but check your gear case for signs of water ingress, ie emulsified oil.

Read the item entitled "Oil leaking around lower unit" on the Engine Frequently Asked Questions board
http://forums.iboats.com/showthread.php?t=207285
 

RadarRick

Petty Officer 2nd Class
Joined
Jun 30, 2010
Messages
189
Re: small gear oil leak

Out of curiosity, is that a crack on the prop or is it part of the casting?
 

hutche

Seaman Apprentice
Joined
Dec 19, 2010
Messages
36
Re: small gear oil leak

ok finally got around to dropping gear oil and didnt look to bad only a small amount of milky oil,took of the prop to find fishing line right up near seal.just wanting to know if the prop seal needs replacing and if so how do i remove this part (See pictures),thanks for the help,also how many litres of oil should the gear case hold?Photo0275.jpgPhoto0274.jpg
 

levi_tsk

Ensign
Joined
Dec 26, 2010
Messages
907
Re: small gear oil leak

my 2 cents is this:
prop seal+fishing line = bad prop seal
have it pressure checked and whats what
 

Sixmark

Master Chief Petty Officer
Joined
Jul 11, 2010
Messages
890
Re: small gear oil leak

ok finally got around to dropping gear oil and didnt look to bad only a small amount of milky oil,took of the prop to find fishing line right up near seal.just wanting to know if the prop seal needs replacing and if so how do i remove this part (See pictures),thanks for the help,also how many litres of oil should the gear case hold?View attachment 81256View attachment 81257

The part that you circled contains orange/brown flecks, this indicates rust, a small amount of milky oil means that water is getting in somewhere, it doesn't matter how small an amount it seems to be. You know that there was fishing line bound up around the propshaft seal, at the very least replace that seal and replace the gaskets on the L/U drain and fill plugs.
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: small gear oil leak

It's pretty easy to remove the carrier on that engine and replace the two propshaft seals. There are two of them, and they go in back to back, so you need to be careful when installing, not to damage the seal lips when driving them in. You might want to consider replacing the carrier oring at the same time. Make sure you put gasket sealer around the outer part of the seals prior to installation.
 
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