Lower Unit Oil Leak

[Juan Grande]

Guys,

Last fall I had water in my lower unit lube. I replaced the drain plug gaskets, but when I launched the boat last Sat. I noticed oil bubbles coming up to the surface. Looked like maybe it was coming from the prop. I know there's a seal in there that can go bad. Just wondering how hard that is to replace or if I should bring it some place? I have a 2005 Mercury 4 stroke, 115 hp.

Thanks in advance.

[dudewheresmyboat]

drop it off at the shop. There is a "special tool" that is required to do the work (or so i've been told). Costs about $300. Get it done asap.

[john.wells]

yep, best bet is to bring it in.

[Finns]

Got an owners manual or repair manual for it?

[Juan Grande]

Yeah, I have the owner's manual. I'm not going to pretend that I'm good at working on motors so I'll probably just bring it in. $300 is pretty steep to replace a seal though.

[jentz]

That special tool is just a wrench,Its a easy work around with a punch and mallet.Remove the prop,the special tool nut and the seal is exposed.Not even a full break down of the lower. You will need a new seal and a washer like nut lock.20 minute job.Just did mine last fall,Cant remember but the seal and lock washer wernt very costly.Less than 20 bucks.

Remove part #20 and replace parts #22 & #23

http://www.boats.net/parts/search/Merc/Mercury/2005/1115F13D4/GEAR%20HOUSING%28PROP%20SHAFT%29%282.07%3A1%20GEAR%20RATIO%29/parts.html

[Juan Grande]

Thanks Jentz!

[jentz]

Thanks Jentz!

Danada amigo.

[boatfixer]

Be dam careful with those 2 "ears" that hold the bearing carrier in

[Juan Grande]

Does the "special tool" help with getting the bearing carrier off without damaging the "ears?"

[boatfixer]

Yes it does. It's not neccesary, you can still remove the carrier without it but if you arnt careful and try to force it out by tapping on the ears you can break them and now u have buy a new carrier. I'm not trying to scare you at all, just making you aware. You can email me at any time for my number if you have any particular concerns.

[john.wells]

Another thing to consider is that the oil may be coming from somewhere else and displaying itself in the prop shaft area. A professional mechanic worth his (or her) salt will pressure test the unit to rule out any of the good seals and correct the problem. I am a professional and see folks do more damage and wind up costing themselves more money a lot of the time when they try to tackle what seems like a simple task and don't have the proper resources available to them. Professionals aren't cheap on the surface, but in the long haul getting the job done right the first time is a bargain.

[Juan Grande]

Good point John.

I replaced the drain plug gaskets last fall. The boat took a pretty hard fall at the boat ramp last summer so I was concerned I had a crack in the lower unit. I had an insurance agent come out and look at it and he said to change the drain plug gaskets, replace the prop seal and if those didn't fix it then have it pressure tested.

Just trying to save a little money I guess. I'll call around and get some quotes from local marine places.

[john.wells]

I hope you find the problem and it doesn't cost too much. I have personally replaced three lower units on my outboard due to Oops's. I am fortunate to have the skills to save me the big money, but I don't have all of the tools to do the job sometimes. My training is in Marine and Power Equipment repair, but have metamorphosis-ed into a heavy truck and equipment technician, so I haven't kept up on the tooling and knowledge for the always changing marine engines. There have been a few occasions where I had to bite the bullet and bring my stuff in to pros who are specialized. It hurts, but what can you do.

[Juan Grande]

So I ended up bringing the boat in to have the lower unit pressure tested. Just got a call from the marine guy and he said there are no leaks and that the prop seal is fine. The only thing I can think of is that the drain plug gaskets were leaking last year which was why my lower unit had water when I went to drain it in the fall. I replaced them before I winterized it and that must have fixed the problem.

[St_Croix_Banks]

What did the pressure test cost you?