Lower Unit Oil Leak

Jewel1964

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Jul 21, 2005
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1987 200ELTH 2 stroke
Oil leaks out this hole in the side of the lower unit.
There was water in the gearcase.
Is this the pitot hole for the speedo?
If it is, might plugging the hole stop the leaking?
lower 2.jpg
 

racerone

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It is NOT the pitot hole.----It should NOT be plugged.----Install a seal kit in the lower unit.
 

Legend850

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Dec 16, 2022
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What is that hole ? It seems to be in an area between the top and bottom filler holes, so it would always be into the gear oil chamber.
 

Jewel1964

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Thanks guys.
I got a closer look at it today. As 90yam40 stated, the hole drains water from the cavity under the water pump (for us northerners). So, I guess that means the leak is in the driveshaft area.
Can I get to the seal(s) from the top, or does the whole thing need to come apart? Maybe have the pros do it and get the skeg fixed at the same time?
Maybe get an Anode (trim tab) for it too.
BTW Racer, I found the speedo pitot. It is on the leading edge of the lower unit. Needed my cheater glasses to see it. It's Tiny.
 

QBhoy

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I wasn’t going to comment and keep my mouth shut…but I can’t quite make out the hole you mean there. Looks like damage to the casing to me. Eyes aren’t what they were these days though.
Anyway…a much simpler way to see what’s what is by the colour and form of the oil you’re seeing.
If it’s blackish grey and smells of fuel, exhaust or 2 stroke it’s perhaps unburned 2 stroke oil making its way out.
If it’s horrible, blue/green/grey emulsified, slimy and offensive to the nose…it’s gear oil.
If it’s indeed a cavity drain, the above applies.

You could also try leaving the engine tilted down further to see if what you are seeing then finds it easier to drain out the exhaust. More likely to be 2 stroke then.

If you suspect it’s gearoil right enough…you could crack open the gear oil drain screw (this itself will tell a story). If the oil in there then runs out freely as it would when the vent or oil level top screw is open and allowing free and vented flow…then you’ve got integrity issues.
Anyway. Likely that I over think such things…but firstly try tilting the engine down lower. As it is in the picture (and assuming that is a drain)…it’s likely offering the path of least resistance for any sort liquid in there…for better or worse.
 

Jewel1964

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I see no evidence of leaks at the prop shaft. I guess I could pump the gearcase full of oil or beyond full and look for a visual confirmation. Or maybe fill it with something to also flush the sludge out.
Regarding pulling the upper bearing carrier, videos indicate that after removing the bolts the carrier should broken free bfore using the puller. They say to break it free by turning or twisting it by tapping sideways on the carrier ears. You would use a punch or dowel. None of the videos actual show this step. Any insight would be appreciated. Like what to use for the punch? Wood, steel, brass ?
 

99yam40

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I would just buy a new seal housing to put back in if you plan on pulling it on a motor that old.

but before doing that I think doing the pressure and vacuum test in your service manual on the lower would be a good idea
 

Legend850

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So finding water in the gear case seems common enough. How do you decide if you need to tear the entire box down, and put in new bearings ? If the gearbox works, the propshaft has no obvious play, what else do you look for to change the response from a basic seal repair, to full tear down ? I found water in my gearbox. I suspect getting the gear carrier out will be a major issue. My obsessive side says do it anyway. My lazy side says repair the leak, see how it goes. What say ye all ?
 

racerone

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??-----Remove lower unit.----Drain oil.----Hurry to your local friendly boat shop.----Have gearcase pressure tested.----Find the leak.----Replace bad seals if leak is found.
 

99yam40

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big question is how long has that water/saltwater been in that gear case?
bearings and gears rust and go south as you keep running even with new lube.
even the smallest bit of pitting will cause failure when run long enough.
inspection would be a good thing IMHO
 

Jewel1964

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Already drained the milk. No boat shops close by (friendly or otherwise). Waiting for a fitting to do pressure test and hopefully find the leak.
Fresh water operation only, but I was also wondering about the internals.
 

saltchuckmatt

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The milk should have separated if it sat awhile. Did plain water come out first?

Id pressure test, fix or not depending on test and run it.
 

racerone

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Driveshaft might rotate at 5000 RPM.----Propshafts rotate at half that.-----I have looked at many seals on 30 year old motors.-----Seal lips are half worn.----They must be replaced !
 

Jewel1964

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Pressure test done. Not leaking at driveshaft and shifter seals. It is leaking at prop shaft seal.
Should the brass spacer simply slide off the prop shaft? It seems struck, but I haven't really tried to get it off yet.
 

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racerone

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It normally slides off.----It might be stuck on the taper.-----Bump with a hammer may break it loose.
 

Bt Doctur

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That area would not cause a leak at the cavity drain hole. You have both a shaft seal and prop seal leaking
 

racerone

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Dec 28, 2013
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Shift rod o-ring is a major leak point.-----Install a complete seal kit !!
 

Jewel1964

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Jul 21, 2005
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Agreed. I will change all the seals.
The brass spacer popped off with a couple of taps from the slide hammer.
I have ordered as service manual as well.
 
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