1971 Evinrude 18 HP lower unit leaking oil - Update

[utah boat owner]

I posted a question earlier and got some feedback. Will try to add pictures and further description. Will try to be brief, but bear with me:

Outboard was bought last winter. Drained lower unit and assumed water in oil (caramel color). Re-filled lower unit and took it out once recently and later noticed light caramel colored oil coming from a "plug" on side of outboard opposite fill plug. Cleaned oil from outside but more came out. Drained lower unit and noted very light caramel colored oil. After draining lower unit no more oil drained from the "plug", so I assumed it came from lower unit oil. Should have taken a picture at that point, but didn't. Took a shot at a backyard repair (no criticism please) and screwed a 5/16 dia. short screw with rubber washer in the recess of the plug, and covered the screw and adjacent area with silicone hoping to seal the leak, and confirm it is the source of the water intrusion in the lower unit (first picture of repair). Took a picture of another "plug" identical to the one leaking for comparison (second picture of similar plug). I have not torn down the lower unit and can't figure out what these plugs are for, and more importantly, can they be replaced. I am new to this and hope my pictures are attached.

Many have been good to offer thier advice. Hoping someone can help me out.

 

[utah boat owner]

Re: 1971 Evinrude 18 HP lower unit leaking oil - Update

Still hoping someone has some insight here!?

 

[utah boat owner]

Re: 1971 Evinrude 18 HP lower unit leaking oil - Update

KFA4304 suggested it is a drain hole, but I'm not so sure. It is some type of plug. Just not sure what it's used for.

 

[kfa4303]

Re: 1971 Evinrude 18 HP lower unit leaking oil - Update

Whoa! That's funky looking Utah. I stand corrected. Quite frankly, I'm not sure what that is. It looks like a homemade "remedy" someone tried. I would try to scrape off the silicone and see what the condition of the drain truly is. There should be a small hole beneath the glob which serves as a drain. The only factory access holes into the gearcase should be the DRAIN/VENT screws and the small Phillips head screw which hold the shift shaft cradle in place. If there is a large hole underneath the silicone, you'll probably have to get a new lower unit housing and/or have the current hole welded shut and re-drill the drain hole.

 

[AlTn]

Re: 1971 Evinrude 18 HP lower unit leaking oil - Update

I've got a '72 18 hp. and where the silicone "patch" is there's a plug that's the same as the one in pic 2. I think they are the equivelant of a freeze out plug in the auto world. Unless you happened to pierce the gearcase housing with the screw the lower plug is above the casting for the gearcase and should be oil tight. At this point it may be best to remove the lower unit and see if you can determine the source of your oil leak. Unless the lower unit oil was milky in appearance you may not have a water intrusion issue.

I'd drain the gear box oil, remove the lower unit, and do a pressure test. If it passes the pressure test put it back together, refill, and go on. If it leaks down, find the source of the leak, fix it , and go on.

Post back with what you find.

 

[kfa4303]

Re: 1971 Evinrude 18 HP lower unit leaking oil - Update

Here's a link that can help illustrate the various drains in the LU of a motor of this vintage.

http://forums.iboats.com/johnson-ev...-lower-mid-unit-water-drain-ports-272510.html

 

[utah boat owner]

Re: 1971 Evinrude 18 HP lower unit leaking oil - Update

kfa4303 - that funky repair was mine! Under it is not a drain hole like the ones in the illustration you included. What that repair covers is a plug like the one shown in the second pic. It's like AITn said, it's like a freeze plug or similar. The second pic shows an identical plug to the one I repaired, but further up on the outboard. I know I am getting water in the LU. After putting fresh oil in and one day on the water and it was a light caramel color coming out at my "repair" site and when I drained the LU. What I'm trying to figure out is what the purpose of the plug is. If it's a freeze plug of sorts, I wanted to know if I can get a replacement.

 

[AlTn]

Re: 1971 Evinrude 18 HP lower unit leaking oil - Update

well in other motors with about the same lower unit there is a drain hole there instead of a freeze plug. What we're trying to explain is that the drain is for a void surrounding the gearcase casting. If you have gearcase grease coming from that area,it's gotten there by leaking from the lower shift rod seal ,the drive shaft seal leaking and finding its way past the waterpump wear plate and housing < unlikely >, or there's a crack in the casting for the gearcase. HOWEVER, it's not unusual at all for a mixture of unburned fuel mix and carbon to leak from that area. If that's what you are seeing you don't have a problem in the drain area. If it's greacase grease some inspection and testing is in order.

 

[utah boat owner]

Re: 1971 Evinrude 18 HP lower unit leaking oil - Update

Update - re-filled the LU with fresh oil and took it for a spin. Same issue, water in oil when I drained it. Looks like coffee with a lot of cream - a light caramel color. AITn suggests doing a pressure test. Is there a procedure for that? Do I just pressurize one of the drain plug holes? Is there a seal kit for my motor? It is a 18103S. Sorry for all the questions.

 

[AlTn]

Re: 1971 Evinrude 18 HP lower unit leaking oil - Update

drain the lower unit, reinstall the fill screw and gasket, pressurize it from the drain screw position to 6 lbs. or so air pressure.If it doesn't leak down after 15 min. or so pump it up to 12 lbs. and wait another 15 minutes. If it's going to leak you should be seeing a pressure loss by now. If you do see a loss, remove the l/u, remove the wp and wear plate so the drive shaft seal is visible, the shift rod seal is visible and the prop shaft seal as well as both drain and fill seals. Pump it up to 12 and use some soapy water to check for leaks at the seals, the gear case halves seam and the screws holding the skeg to the gear case. The tube in the hand pump kits for the l/u pump filler makes a good adapter for a pressure pump.

Yes, seal kits are available for your engine model.

 

[utah boat owner]

Re: 1971 Evinrude 18 HP lower unit leaking oil - Update

I noticed there are seal kits under Sierra and Mallory. I assume they are just different manufacturers and either kit will work. Correct me if I'm wrong. Also, there are several o-rings. Does anyone have an exploded view that shows where they all go, or does the kit include that info?

Thanks again for all the help.

 

[kfa4303]

Re: 1971 Evinrude 18 HP lower unit leaking oil - Update

I usually get the sierra kits and have had good luck, but you can also buy official Johnson parts. You're right that there are several o-rings. One goes on top of the drive shaft, one goes on the prop shaft bearing, one under the shift shaft rod bearing, and there's the spaghetti seal as well, which you'll have to cut to length. Here's a link to a pic.

Evinrude Gearcase Parts for 1971 18hp 18103S Outboard Motor
Evinrude / johnson 18-20 hp LOWER UNIT disassembly - YouTube (LU dis assembly vid)
http://forums.iboats.com/johnson-ev...l-kit-1968-evinrude-fastwin-18-hp-601481.html (handy link)

 

[utah boat owner]

Re: 1971 Evinrude 18 HP lower unit leaking oil - Update

KFA4303 - thanks for the great information! I ordered a seal kit from Iboats and am waiting for it to arrive. I did get ahead of myself and need someones thoughts. After draining the oil/water from the LU, I did remove the LU and unscrewed the skeg (I believe thats what it's called) on the very bottom of the motor. That was before I leak checked it. Probably should have leak checked it first as AITn suggested, but I did put it all back together and leak checked it. No leaks at either 6 or 12 PSI. I even had it in a tank of water to look for leaks, but it held - no pressure drop after 30 minutes. I can't believe it healed itself. I am planning to put in a new seal kit and also ordered a drive shaft seal. Should I replace anything else? I will of course replace the impellor while I'n in there. I did notice that two of the "fins" on the impellor were facing each other, so whoever put it in didn't pay close attention. I was planning to leak check it again after all the repairs. Any other advice? Again, thanks to all who give of their time and experience. You are providing a valuable service to folks like me.

 

[kfa4303]

Re: 1971 Evinrude 18 HP lower unit leaking oil - Update

I think you've got it covered. A new impeller, LU reseal kit, clean the carb and she'll be like new.

 

[AlTn]

Re: 1971 Evinrude 18 HP lower unit leaking oil - Update

sounds like you" healed" it, or whichever, drain or fill, screw you removed to pump air into was the culprit all along. It also helps to turn the drive shaft clockwise some while testing as it either it or the prop shaft may have a small leak only when the seal surface is in a certain position. In other words try to induce a leak.Seems like member James_12345 has posted on a seal replacement job recently if you can find his thread.

 

[james__12345]

Re: 1971 Evinrude 18 HP lower unit leaking oil - Update

The seal replacement thread is the third link kfa4303 posted in post #12 of this thread. Here it is again http://forums.iboats.com/johnson-ev...l-kit-1968-evinrude-fastwin-18-hp-601481.html I'm finally done with it, but I haven't got to upload the pictures due to having misplaced the memory card adapter for my computer. I'm out of town for the week, but as soon as I get home I'll try to get that thread finished.

 

[utah boat owner]

Re: 1971 Evinrude 18 HP lower unit leaking oil - Update

OK, got the LU torn down, still waiting for the seal kit, but have two questions. Does the seal kit come with an o-ring that will fit the shift rod? I seem to see a bushing in the LU under which is the o-ring. The bushing is stuck in there pretty good. Any way to get it out without destroying it? I am looking to replace anything that may allow water in the LU and the shift rod seems like one place to introduce water. Also, several have mentioned 847. What is that and is it recommended? Sounds like a sealer.

 

[kfa4303]

Re: 1971 Evinrude 18 HP lower unit leaking oil - Update

HI Utah. Yes, the kit will come with a small, very thick o-ring that goes under the shift rod bushing. You remove the busing itself by tapping it out of place. You can either use a special tool and/or use a spade bit and a socket extender. Here are links to both methods as well as a a pic of a basic lower unit reseal kit with all the bits labeled.

http://forums.iboats.com/johnson-ev...l-kit-1968-evinrude-fastwin-18-hp-601481.html (see post #11 for how-to on the bushing removal)

http://forums.iboats.com/johnson-evinrude-outboards/fastwin-lower-unit-seal-faq-277190.html (the DIY method)

Evinrude / johnson 18-20 hp LOWER UNIT disassembly - YouTube
HOW TO PULL SEALS FROM LOWER UNITS - YouTube