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bass_hunter

How to tell if water is getting in lower unit gear case?

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HI, I have a johnson 1969 55hp 3 cylinder hydroelectromatic engine I recently bought. The guy I bought it from said water was getting into the lower unit by the gears. He wasn't for sure. How do i tell if water is leaking in. I did run it with some muffs hooked up to a hose. It seamed to idle and shift fine. Only thing I notice was that I saw a little bit of white smoke. If I have bad seals can Any one tell me how to replace them or how much they will cost to get replace.

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Your gear case oil will be milky in color if water is mixed with it. When was the white smoke coming from.

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Did the white smoke come from out of the prop inner hub? If so, it's supposed to. That's where your exhaust is coming out.

As stated earlier, if the lower unit seals are leaking the oil will be milky white.

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I took off the prop and wiped the inside with my finger and it was a dark brown color. I thought the smoke was coming from the upper part of the lower unit by where it connects to the engine itself.

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will the water coming out of the pee hole be hot if you are getting water in your gearcase?

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will the water coming out of the pee hole be hot if you are getting water in your gearcase?

No. The water should be warm, however. It's a small portion of your engine coolant.

The inner prop area should be dark. It's exhaust. Just like sticking your finger inside your car exhaust only it should be somewhat gummy as it's been underwater.

The exhaust travels from the engine and via the exhaust port in the lower unit out the prop area. There is a seal for the exhaust where the lower unit bolts to the upper section. However, the exhaust is it's own port. If exhaust is getting into the lower unit gearcase that would tell me the gearcase itself is cracked. Not common, but can happen.

Pull the lower unit lower oil plug and let a small amount of oil drain out. If it's milky white then you are getting water in the gearcase. Most likely the water is coming from a leaking lower unit seal but it's tough to tell for sure without seeing it. If you're somewhat mechanically savvy, you can hook up a regulated air line to the oil plug for the lower unit. Slowly pressurize it to 15 psi, then shut the air off. If it holds pressure then slowly bring it to about 20 psi and shut the air off. If it holds pressure, then the seals are good.

Most important, if your lower unit oil looks like oil and not milk then your good to go.

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I can't answer that without knowing the condition of the oil.

You have to drain out a small amount, just enough to see it. If it's milky white, you probably have bad seal(s).

If it looks like good oil then your seals are probably fine.

Water churning in the oil will make it look milky white.

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The lower unit is a gear case. To keep water out and oil in it uses seals. There are seals on the drive shaft under the water pump, seal on the impeller housing(cap), prop shaft.

If you look at the bottom of the lower unit you'll see a oil drain plug. Up higher on the lower unit just above the cavatation plate is another plug for oil level and air bleed.

Remove the lower plug, next remove the upper plug. Oil should come out. If water, milky oil, or nothing comes out you need new seals. You could do a pressure test to see which seal is bad but considering the year you'll want to change all of them and a new impeller for the water pump.

Fill the lower unit with the proper oil. That would be Outboard Lower Unit oil, you fill from the bottom hole till it comes out the top hole (oil level and air bleed hole).

You should buy or get an manual from the library to do this job. Or bring it in an have it done. Parts will be around $50 plus one, two at tops hours labor.

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Has the gear oil been changed since it has last been run in the water, do you know? The reason I ask is if it has, you might not have water in it yet. Running it on the hose won't let water in unless the seals on the drive shaft are nearly gone. Even at that, there usually isn't enough water and pressure from a hose to begin with compared to sitting in the water.

If when you inspect the oil as boilerguy mentioned, if you don't see any water or milky colored oil, don't assume it's ok just yet. The guy you bought it from knew it had a problem and hopefuly sold it to you with good clean oil in it. You could either run it in the lake and check it often or have a pressure and vacuum test done on it just to be sure.

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I checked it this morning and it was a yellow to tan looking. a little translucent.

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That is an indication that water is starting to get in. I don't know how mechanical you are. If you're good with a wrench I'd recommend getting a service manual and following it to replace your seals. If you're not mechanically savvy a trip to a dealer would be my advice.

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