55 Fleetwin Gear Case Leak? W/ Pic

[crackburglar]

Hi-

Having dropped the lower unit to verify I had the plastic impeller housing before I ordered an impeller, I found what looked like a gear oil leak that mixed w/water. It's classic milkshake look of oil/water. But after pulling the gear oil plugs and draining the oil, and while the gear oil looks old and discolored, it doesn't look like it contained water.

What would I do to fix this?



THANKS for thoughts!

 

[Daviet]

Re: 55 Fleetwin Gear Case Leak? W/ Pic

Looks more like oil/fuel mixture that was not completely burnt in the engine.
If there was no water in the lower unit and it was full, I wouldn't worry about resealing the lower unit, clean it up and install the lower unit.

 

[crackburglar]

Re: 55 Fleetwin Gear Case Leak? W/ Pic

Daviet, would that have come from exhaust, or a bad gasket up above. That creamy mixture was about half way up through the Driveshaft Casing, and above that just looked like oily.

Thought I might try to get to the bottom of this and if parts were needed to get them on my already growing impeller/carb kit/ head/base gasket order.

 

[Scurvy Knave]

Re: 55 Fleetwin Gear Case Leak? W/ Pic

your gear oil looks kind of "wet" to me. Might be a small leak. Unburnt fuel/oil is usually darker than that - but that white cream looks like gear oil. Check the smell of it. If it smells kinda burnt like exhaust, then it's unburnt fuel. If it just plain stinks - it's probably gear oil.

Sealing the gear case on this is no biggie - so why take the chance while you have the power heard off?

 

[crackburglar]

Re: 55 Fleetwin Gear Case Leak? W/ Pic

Scurvy- It has a burnt exhaust/gas smell. And when I drained the gear oil, indeed it just plain stunk. The unburnt gas/oil buildup makes perfect sense to me since when I bought the unit it was only firing on 1 cylinder (due to one point that never closed).

I'd assume the guy I bought the motor from had less a clue than I did. He told me he had checked the gear oil and it was full. Shortly thereafter (on iboats) I found out the drain/fill screw gaskets are one time use. The gaskets were essentially broken down to nothing.

What would it take to seal the gear case since I have this all open?

 

[Scurvy Knave]

Re: 55 Fleetwin Gear Case Leak? W/ Pic

Well, if the drain seals were re-used, a small amount of water might have gotten into the gear case.

you can buy a seal kit pretty cheap. I think Iboats carries it too. You will also need a gasket adhesive/sealant. I like to use the permatex aviation stuff, but spec calls for some 3m stuff.

Tool wise, you will need a basic seal puller, and either a special tool to punch out the shift-shaft bushing, or some ingenuity. Check some threads on here, you can punch out the bushing using a spade drill bit with the right size shank.

Other than that, resealing the gear case is quick and easy.

 

[crackburglar]

Re: 55 Fleetwin Gear Case Leak? W/ Pic

I can't thank you guys enough! The short time i've been on here has been nothing but encouraging for me. I think I'm going to opt for the new gaskets (buying a couple pairs of them) and use it as is, then about half way through next season I'll check the gear casing and impeller housing for leaks of water or oil and proceed accordingly then.

 

[nwcove]

Re: 55 Fleetwin Gear Case Leak? W/ Pic

also looks like normal unburnt fuel oil to me. ( looks like you are running red omc oil!!)

 

[HighTrim]

Re: 55 Fleetwin Gear Case Leak? W/ Pic

Wow that impeller was toasted wasn't it! How old was it?

Looks like unburnt fuel/oil mixture. How was the carbon seal assembly at the top of the driveshaft. That assembly is CRITICAL on your motor. Ensure it is all there and in good condition. Also, ensure you are firing consistently on both cylinders.