Water in lower unit?

[blackwaterstout]

Darn this is frustrating. Finally went out and got to run the boat in today and everything seamed to go well.....until we trailored the boat and took it home. After getting home we noticed that there was a little oil leaking from the lower gear case out of a weep hole. It looked to me like it was a little milky. The gear lube was replaced a week ago after installing a new water pump.<br /><br />I took a few pictures. Before anyone asks, the oil that is on my lower case in the picture came after I unscrewed the top drain plug to check the lube. It was not leaking like that. It was seaping a little out of that small hole above the cavitation plate. I've never seen a water intrusion in a gearcase so I'm not 100% sure what I'm looking for, but I've heard it will look milky. Can anyone tell from those pics what exactly is going on. This is my first outboard and it's a learning experience.<br /><br />A little background information. The motor is a '79 Johnson 25 and had the impellor and water pump housing replaced a few weeks ago. I replaced it with the Sierra 18-3383 from this website http://www.sierramarine.com/catalog_pdf/Sierra_8023-166.pdf <br /><br />The kit was actually a little different from the pump that was on the motor and I'm hpoing that I got it put back together properly. IT's peeing nicely and cooling the engine so I assumed I put it back on right. Can someone take a look at that kit and maybe explain how it's installed or give me an installation diagram? Where do those oring go? <br /><br />Anyway, I'm pretty frustrated right now because we've been working so hard on this thing and every time we think we're in the clear something pops up. What should I do next? The pictures are located at http://www.picturetrail.com/gallery/view?p=999&gid=8354571&uid=3956417&members=1

 

[kajnjim]

Re: Water in lower unit?

BWS, are you sure that it was gear case lube coming from vent above the cav plate, and not oil from exhaust? If you are sure it is, then it must be an issue with a seal somewhere between gear case and water pump. I'm certainly no expert, but that would seem logical to me anyway.

 

[timmathis]

Re: Water in lower unit?

What does the lower unit gear oil look like? Tim

 

[blackwaterstout]

Re: Water in lower unit?

There is a picture of the lower unit gear oil in my original post. It's a little milky. Not horendous, but not as clear as when I put it in there. <br /><br />Jim I'm pretty sure it is. It looks and smells the same as what is in the gearcase. I guess I'll drain it totally tomorrow and refill it with fresh lube. I hate to pull the lower unit off but I guess I will have to. Like I said in the original post, I replaced the waterpump a few weeks ago and it did not come with an installation diagram. I called Sierra about it and they promised to send me a install diagram. They never did. I assembled it as I thought was logical and after test running it felt confident that I fixed it correctly. But Sierra kit came with an o-ring instaed of a seal and I was a little confised as to where it went. Maybe I got something wrong. I still can't seem to come up with a single installation diagram of a sierra water pump kit anywhere on the net. <br /><br />Maybe someone can take a look at Sierra pump 18-3383 from this site http://www.sierramarine.com/catalog_pdf/Sierra_8023-166.pdf and tell me exactly how it gets assembled.

 

[kajnjim]

Re: Water in lower unit?

Is the o-ring possibly for the drive shaft? Never have used the Sierra kit. The definitive way to figure out where your leak is, is to perform a pressure/vacuum test. Just do a search in this forum for specifics on a pressure test.

 

[blackwaterstout]

Re: Water in lower unit?

I added another pic of my situation. It's an older picture of the motor before this incident happened. Pay close attention to the smaller ooze that is on the right. Thats the same hole that wa leaking today.<br /><br /> http://www.picturetrail.com/gallery/view?p=999&gid=8354571&uid=3956417&members=1 <br /><br />You can see in the pic that there is a big black oozing of oil coming down across the gearcase. But there is also a smaller oil ooze to the right of that. It's harder to see but it is at the front of the motor about 1 inch below the joining of the gearcase the the exhaust housing. That is the hole that leaked the fluid today. In fact, it leaked the ooze onto my transom support. Thats how I first saw it.

 

[kajnjim]

Re: Water in lower unit?

Same place I found the air leak when I pressure tested mine. Never noticed lube leaking from it, but I'm sure thats where the water was getting sucked into the gearcase.

 

[blackwaterstout]

Re: Water in lower unit?

What are those holes anyway? I assume vent holes, but wouldn't that allow water to seep in? What the heck can be done about that?

 

[itstippy]

Re: Water in lower unit?

That little weep hole is above the sealed portion of the lower unit. It is to allow water & unburnt fuel crud to weep out. Looks like it's doing it's job. That stuff coming out is black and nasty and is unburnt fuel & carbon deposits and exhaust soot mixed with water from the leg.<br />They do not put weep holes in the sealed portion of the gearcase.<br />Drain some oil out of the drain hole in the lower unit into a clean glass jar. If it's milky then you have water intrusion. This could easily be from the fill and vent plugs themselves - you replaced the plastic washers, right? Don't worry if it's a bit discolored - look for milkiness.

 

[blackwaterstout]

Re: Water in lower unit?

For the record the picture I posted of the dark black crud is an older picture. That is not what it looked like today. Today it was weeping the light colored mixture in the other two photos I uploaded. The stuff coming out of the weep hole looked like the stuff coming out of the vent hole of the gearcase. I will verify this tomorrow morning. I guess that would indicate that water is moving back and forth through the driveshaft seal because it is getting into the gearcase and at the same time it is coming back out of the gearcase and weeping through those holes.

 

[Moody Blue]

Re: Water in lower unit?

BWS this sure looks similar to a problem I was chasing earlier this season on my Mariner 40HP. Had oil seepage out the same weep hole and was getting water in the L/U so I replaced the fill/drain screw washers first (cheapest ) but didn't fix it. Pulled the L/U and did a waterpump rebuild and at the same time replaced the driveshaft seals below the waterpump housing. Put everything back together and still water in the L/U. Took it apart again and replaced the shift shaft seal and presto - no more leak. I wouldn't have thought that a seal on a shaft that rarely rotates would wear out. Lesson learned. <br />If you have water in the L/U, when you pull the drain screw (bottom) the water should drain first then the oil.

 

[jameswilson95]

Re: Water in lower unit?

BWS I had something similar with my 40 hp evinrude. Follow the link to photos of goo oozing out of small drain hole.<br /><br /> click here <br /><br />I now realize after many a conversations and much money on seals etc. that its just goo collected in the bottom of the leg after running engine

 

[blackwaterstout]

Re: Water in lower unit?

James95...... That is exactly what mine looks like. Although in my case it not only comes out of the drain hole, it is also the same stuff that is in my gearcase. I don't think that should happen in the gearcase.<br /><br />RodC, I will be sure to inspect the seal around the shift linkage if and when I pull the lower unit off again. I am going to first try new drain plug washers. Although I'm not optomistic that will work. But it's the cheapest fix.

 

[blackwaterstout]

Re: Water in lower unit?

By the way, in the event that I have to replace either the driveshaft seals or the shift linkage seals, will I be required to pull the actual gear case apart or can I just get away with pulling the lower unit? And if it's the lower unit only, will I actually have to pull the driveshaft off or will the seal fit over the driveshaft?<br /><br />I'm fairly comfortabele pulling the lower unit, but actually taking the gear case apart makes me a little nervous.

 

[kajnjim]

Re: Water in lower unit?

You will not have to pull the drive shaft or open the gearcase. You just have to pull the LU to access the seals. After driveshaft seal is replaced, the driveshaft will slide past it into the gearcase.

 

[blackwaterstout]

Re: Water in lower unit?

Is it OK to pull the driveshaft away from the lower unit? I thought that if the driveshaft came out of the lower unit the gearcase would have to be disassembled to realign the pinion gear?

 

[kajnjim]

Re: Water in lower unit?

When you drop the drive shaft back into the gearcase, it will realign itself with the pinion gear. You will feel it reseat itself when you drop it back in.

 

[blackwaterstout]

Re: Water in lower unit?

Ok. What about the shift shaft seal? Don't see how you could replace that seal without pulling the gearcase?<br /><br />FYI, I replaced the lube yesterday with fresh lube and took the boat out fishing. Did not run it much other than maybe 1/2 mile just to get to a fishing spot. WHen I came back we checked the lube. It was still a little milky. Not as bad as yesterday, but you could tell that water had gotten in somewhat.<br /><br />One last question. How tight should the drain and vent screws be tightened? I was talking to a guy that said those screws should be super tight. He suggested taking an impact screwdriver and wacking it a few times to tighten it really hard. I seriously doubt that water is getting in via those screws, but it would be the easiest thing for me to test first.

 

[kajnjim]

Re: Water in lower unit?

The shift rod seal (o-ring) is accessed in the same way the drive shaft seal is. Yes, the drain and fill screws should be fairly tight. The most important thing regarding these are the washers, though. I'm at work and don't have the manual with me, so I can't tell you exactly what the torque specs are on them.

 

[Goodoleboy]

Re: Water in lower unit?

If it were me I would drain lower unit and refill with diesel fuel and let motor idel for a couple minutes in gear forward and reverse. Couple minutes now not a half hour.<br /><br />Drain and do it again until all old watery mix is removed. Diesel has enough lubrication to protect gears at low rpms and no load.<br /><br />Once you have gear case cleaned real good refill with new oil and put new o ring seals on fill and drain screws. Tighten just as dad gumed tite as you can with a BIG flat tiped screw driver.<br /><br />It helps if you stick your tounge out one side your jaw and when you think youve got it real tite then switch sides and giver one more grunt....Grin!<br /><br />Good luck!