Lower Unit Leaking Grease

Robert16star

Cadet
Joined
May 13, 2007
Messages
14
20071118_IMG_2448_1.JPG

20071118_IMG_2451_1.JPGI drained my lower unit and because I had some ice in a bucket of water nearby I thought it might help the draining process by warming the lower unit with my propane torch. Well I'm not sure but I don't think it helped. After refilling with new grease I next started the engine (it took a bit as it hadn't run in three months). Once I had it running it wasn't long before I had grease oozing out of the vent holes above the prop and from out behind the propeller it's self.

Not good right?

I re-drained the grease for fear there would have been water in there and didn't want to leave it that way with temps dropping. It doesn't seem to be leaking when not running but I'm almost certain it will once I run it again.

I've attached some lovely photos that I hope you can take a look at.

Did I melt a gasket or seal? Is that where the oozing grease is coming from? Can I it make it right by spring time.
 

Lakester

Chief Petty Officer
Joined
Nov 17, 2007
Messages
428
Re: Lower Unit Leaking Grease

hello~

OOPS! seems to be the word of the day on that one. gosh...

i am no expert, but on speculation alone... given the volume of oils, u may have gotten it hotter than the seals could handle. they expanded and the oil's viscostiy thinned... and you have have atmospheric variances too. hot air expanded some inside, to a cold outside. so had pressure pushing thinner oils. i bet if u just drain and normalize temps in system prob will be fine since i see no burn marks on l/u's paint. and when in water, down under... cooler there, so seals tighter and viscosities thicker... ie no leaks...

but as i say, just speculation. makes me think. and i may be pulling mine down, so good to see this mistake. we learn many ways.

maybe hot water would have been better, well warm. in alaska where temps drop into the -s routinely during winter, they have heater tents for the bush plane's engines. they heat up engine and normalize oils, parts before attempting starts. just too cold otherwise to ... even get it to rotate cold.

"CLEAR! ~ switch ON; click, click... click.... click.... " lol~

wonder what the experts will say on this one?

[lakester hollars down the hall... "honey, no, guess we wont use the torch on the lower end this afternoon... thanks... " lol] :rolleyes:

regards
lakester :cool:
 

HighTrim

Supreme Mariner
Joined
Jun 21, 2007
Messages
10,486
Re: Lower Unit Leaking Grease

Im sure alot of that is carbon (unburned fuel oil mix). Comes from excessive trolling, idling, etc... How long did you have that torch on it? I cant see long enough to damage the seals. This thread will help you with this. Just check the lu oil level tomorrow and ensure that it is still topped up, if so, Im sure you're ok. Good luck.

http://forums.iboats.com/showthread.php?t=207285
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: Lower Unit Leaking Grease

I think what you are seeing is unburned fuel and oil that has been discharged out the exhaust. Byproduct of running on a hose, combined with cold weather, combined with hard starting/raw fuel going through.

It'll be OK.
 

Robert16star

Cadet
Joined
May 13, 2007
Messages
14
Re: Lower Unit Leaking Grease

I hope you are right. As much as I would enjoy the challenge of replacing the seals, at this point I'd rather rest easy (all winter) and wake up in the spring "leak free".

Thanks to all for posting..............

One question though. The grease that appeared was of a thick variety. Not close to what I would think it would look like as you are suggesting. Although after I got it running, and it took some doing, the engine did smoke a great deal.
 

HighTrim

Supreme Mariner
Joined
Jun 21, 2007
Messages
10,486
Re: Lower Unit Leaking Grease

It is fairly normal. Remember, not all fuel gets completely burned up in the motor, and so, not all of the oil gets completely burned up either. Since gas has a tendency to evaporate , that leaves just the oil, hence why it seems so thick to you. Combustion is even more incomplete during idling (trolling or on the muffs). The unburned oil will be thick, black and sooty as in your pics. I wouldnt worry. Just dont forget to check the level of your lu oil tomorrow for peace of mind.
 

Gary H NC

Fleet Admiral
Joined
Dec 1, 2005
Messages
8,972
Re: Lower Unit Leaking Grease

You should be able to tell by smelling it.If its gear lube it will have that strong smell. It looks too dirty to be gear lube to me.I think its unburnt 2 stroke oil.
Mine did the same thing when i winterized it a couple weeks ago.I ran it on the muffs then fogged it until it choked out.I noticed it had dripped a lot of oil out around the prop.
 
Top