8HP leaking gear lube, searched EVERYWHERE to no avail. Photos inside.

[flynavy812]

Hello everyone, I'll try to keep this brief. Acquired this engine with a small john boat, previous owner was very clear about potential seal issue. Said lower unit seals are "bad" and gear lube leaks. He stated that everything runs fine and that he just replaces gear lube every 5-6 trips, and it shouldn't be a problem on this engine. He also mentioned he had someone come out to "fix" the issue but nothing really changed.

Skip forward, I finally took the boat out and everything ran just fine. I know this is probably a bad idea, but to be honest I don't want to dumb a lot of money into this, and I might have to sell in a few months if I need to move for work. So I put fresh gear lube in prior to the first trip to be safe.

So, initially I could see gear lube leaking out of the drain screw area, upon the first draining I realized there was no gasket so I was hoping this would be an easy fix. Added new gasket after filling up with fresh lube. Let it sit overnight and no more leaking from the drain screw area, or anywhere else.

Next day I notice gear lube is now "leaking" NEAR the vent screw area. It might be hard to tell from photos, but there is a very very small hole near the vent screw/bump looking thing in the photo. Upon closer examination, I can see what appears to be rubber/gasket material kind of blocking the hole. So I'm not sure if this is supposed to be sealed? Maybe a gasket to the other part of the lower unit is bad, allowing gear lube into this area, where lube would normally not be found?

So here is my problem, everywhere I've called said it will be a roughly 2 hour job, at around 90.00 per hour in labor. Am I an idiot for thinking I should just keep running it, while being diligent on the gear lube levels?

Should I just look for another lower unit? Are any other lower units compatible with the 8HP I have?

Should I just look for another small used motor in good condition?

This engine is in great condition other than this one fault, a lot of things have been recently replaced. I just don't want to dump too much money into an already cheap project, but I also don't want to get stranded if something goes bad. Any advice is appreciated, if any other photos are needed I will get them ASAP.

 

[racerone]

Facts #1---Those lower units are not considered robust.-----# 2 they are a much sought after item.-----#3--------Fairly easy to install new seals yourself.-----Only challenge might be removal of propshaft bearing / seal carrier.-----It has a lefthand thread and " special tool " required.-----A shop would likely remove that for pennies.

 

[flynavy812]

Facts #1---Those lower units are not considered robust.-----# 2 they are a much sought after item.-----#3--------Fairly easy to install new seals yourself.-----Only challenge might be removal of propshaft bearing / seal carrier.-----It has a lefthand thread and " special tool " required.-----A shop would likely remove that for pennies.

Much appreciated. I did buy a Mercury repair disc that outlines assembly and repair of lower units, it covers a broad range of HP types though. I've read that removal of LU requires some links to be removed or disabled, any idea if this is the case? Or is it simply unbolt and slide off?

 

[racerone]

Shift rod disconnects at the top.---Very simple disconnect.-----Reverse lock is removed as well.---Visible aroubd the swivel bracket.

 

[flynavy812]

Shift rod disconnects at the top.---Very simple disconnect.-----Reverse lock is removed as well.---Visible aroubd the swivel bracket.

I'll be honest, not really sure what any of that means so I have some reading to do. Would I be wise to remove lower unit and bring to shop on its own? Curious if that will save me any money if I just have them do seals but at least get it started.

 

[racerone]

Yes, best to hire the shop I think.

 

[flynavy812]

Yes, best to hire the shop I think.

Small update I'm hoping you can help with so I'm not making a bunch of posts. Took boat out, came back, and drained gear lube. Gear lube is not milky and shows no signs of water. However, only after running it do I get a small leak of water/lube combo that comes out of this small hole near the vent screw. It kind of trickles out for an hour or so and then stops, but I'm not seeing any water when I actually drain the lube. So is this the seal on top of the lower unit?

 

[Chinewalker]

No - it is not gear lube. It is unburned fuel and oil mixed with water that is draining down from the powerhead once you stop running. It tends to build up in the motor leg, particularly during extended periods of idling or trolling, but can build up some under any conditions. Typical of most 2-strokes. That hole is there to drain the leg as there are various casting cavities in the unit that would collect water and freeze if left undrained. I'd call it more or less normal.

 

[robert graham]

Maybe remove prop and inspect for fishing line or seaweed wrapped around prop shaft and/or under prop shaft seal causing a leak and/or sear damage?.....easy enough to check and you'll be needing to inspect the prop shaft area anyway.....

 

[flynavy812]

No - it is not gear lube. It is unburned fuel and oil mixed with water that is draining down from the powerhead once you stop running. It tends to build up in the motor leg, particularly during extended periods of idling or trolling, but can build up some under any conditions. Typical of most 2-strokes. That hole is there to drain the leg as there are various casting cavities in the unit that would collect water and freeze if left undrained. I'd call it more or less normal.

I've seen this mentioned before and was hoping it was the cause, but the oil that is seeping out is still a tan color like the gear lube I drained and filled with. Now, when I drain the actual gear lube the drain screw area let out the gear lube but also a very very faint black streak which I assumed was unburnt oil.