Gear case

[T-water]

Hey Folks

Unfortunately I'm not fishing (actually I just had my first kid so life is good). So I've been attempting to do long overdue maintenance on my 30HP 4 stroke Honda. As I was pumping oil into the lower unit waiting for it to spill out the top screw the oil started coming out the water intake vent???? The oil was also coming out the overflow screw as well so I tightened the screw and cleaned everything up... Am I good to go? why would the oil come out the water vent? the vent is parallel with the overflow but it still doesn't make sense to me.

Any help would be awesome, especially the news that it's no big deal!

[Valv]

That is NOT a good sign. I would have a dealer/mechanic do a pressure test on it. It should only come out of upper hole.

[T-water]

Thats what I thought, I will add that the motor ran great this spring and there was no water in the oil when I drained it. What happened?

[marine_man]

When you say no water came out - was the lube milky colored at all?

marine_man

[T-water]

no it wasn't milky at all it was completely black?

[T-water]

Okay I just talked to a repair guy he said I likely blew a gasket while I was pumping in the oil. The reason was that I took some bad advice off of the internet and did not completely remove the venting screw! So wile I ws pumping it put a lot of pressure on the gasket, still seems hard to believe that my little plastic pump could put enough pressure on the gasket to bust it but thats what it looks like.

[marine_man]

Ok.. it makes sense now.

Yes, you always want to fully remove the top screw - that's the only way you know if it's full.

Were you using a pump or squirting oil from the tube into the hole?

With a pump I could see how you could potentially build up enough pressure, but if you're just squirting it in with the tubes I would think it would be difficult.

Either way pulling the lower unit and having it checked out is the direction to head in.

marine_man

[boatfixer]

You can do the same thing to a mercruiser from filling to fast. The passage between the housings is quite small and if you try to fill fast, you will push the oil past the seals under the water pump.

[T-water]

So what kind of money am I looking at spending? This seems a bit beyond my level of wrenchery! What will they do? What needs to be replaced?

[boatfixer]

I'll bet most shops will want to reseal the whole thing with a kit, so you're looking at 2-3 hours labor (flat rate) and a kit. Depending on your "wrenchery" (I like that term), pick up a service manual and give it a try.

[Surface Tension]

Get a manual, you should have one any way so that cost is mute.

Replace the drive shaft seal and the shift rod seal. While your at it replace the impeller. The black oil would concern me, maybe just oxidized aluminum. I'd check the lower unit oil after the first use and periodically after that.

[eurolarva]

I dont know your motor so this is just a generic response. If you can remove the lower unit and get to the drive shaft seal then try pumping a bit more oil the way you did it you might be able to see the seal that is bad. A drive seal is normally pretty easy to replace and a lot cheaper then a complete lower seal kit with install. Best alternative is to have a mechanic do a pressure test and if it is only one seal it might be cheaper. A lower unit seal kit install can run between $200 to $500 depending on the size of the motor and the place you take it.

[T-water]

Thanks for the replies! I think considering the possibility for calamity is leading me to leave this to the professionals (that and with the little one I rarely get more than an hour in the garage at a time). Anybody have some ideas for a good honest Honda outboard repair shop around the metro.

[AngelicFatum]

I agree with euro (btw are you the same eurolarva from another water-related site), and boatfixer, if you have reasonable wrenching skills you should be able to get the lower unit off. A manual is always a good investment, try hsolist or honda- a specific manual is better but the seloc would help.

A water pump is also not that hard to DIY(depending on your skills), but you should prolly have it replaced no matter what.

When was the last time you changed the gear lube? If it had been awhile that might be why it was so dark.

Good Luck

[eurolarva]

I agree with euro (btw are you the same eurolarva from another water-related site), and boatfixer

This site is better because it is home and mostly covers fishing.

[note from admin: please read forum policy before posting again. thanks!]

[T-water]

The final chapter (I hope). Due to time constraints and my concerns about makin matters worse I brought my boat to Dans Southside Marine. They charge about $100 to assess the problem I figured they'd let me know if it was a repair I could do or not.

They checked it over and pressure tested everything said they found no problem!!! So I'm thoroughly confused but thankful. Gonna pick it up tom. and give it a test drive.

Thanks again for the feedback.

[Surface Tension]

You said the oil was completely black. Are you referring to the color of the lower unit oil when you drained it or was it the color of the oil that was leaking out? The way you described this you lead me to believe is was the color of the lower units drain oil, which is odd and I made mention of that.

I have a feeling its two separate things here. Was the motor on the boat of was it laying down?

[T-water]

The black oil was the oil dripping out of the gear case which may have appeared more black then it rally was due to the oil pan being black (why don't they make white oil pans LOL). The motor wasn't sideways although that would explain it.

I picked up the boat today they did vaccum and pressure checks, siad it's all good.