Gear lube problems

I have a 1970 Evinrude 85HP V4... bought it used, powerhead and everything runs great. I first started to notice it was overheating so I took off the lower unit and found that the nylon water pump housing had MELTED, and the impeller obviously was in horrid shape as well.

Anyways, at the same time I had checked the gear lube and been changing it. It has been coming out pure white, so I figure I had a leak somewhere. After I replaced the water pump I took it out, ran great didn't overheat, but my gear lube was still white when I went to drain it.

Checked the plugs and noticed the lower drain plug didn't have a seal on it, duh. Well I replaced the seals and took it out again. Gear lube is still white, to make matters more interesting it's leaking this milky lube out of the weep hole on the portside of the motor on the lower unit. I believe this is an outlet for water from the pump as it pisses a little when on muffs.

Either way, when I was in the motor I pulled the upper bearing housing below the pump and replaced the seal on it. I also replaced all the seals on the pump itself and the shaft seal/rubber boot above it. Any ideas where I'm getting water in, or why it's leaking lube out of that weep hole?

Both inlet/outlet water pipes looked ok, one was kinda crimped a little but I straightened it out. Also to note--prop seals looked fine when I had that apart. Also to note, when I first got the motor I changed the gear lube right away and it was black, no indication of water--and supposedly run 2 days prior. This led me to believe that the seals on the drain/fill screws were the issue.

Any helps is appreciated, thanks.

Re: Gear lube problems

Probably need to pressure test the L/U to see where it's leaking. You can get a pressure gauge on Ebay for about $30 or take it to a repair shop and have it tested. Pump it up to about 10psi and you can either listen for the leak or spray the various seals with dish soap solution. Or test it underwater. I suspect the prop shaft seal is probably your problem. That "weep hole" is a drain hole and perfectly normal to see water/oil coming out.

Re: Gear lube problems

So for example if I overfilled the diff, then I would see gear oil coming out of that hole? Still means it had to come from somewhere I guess... figure even if the prop seal leaked, why would I see gear oil coming from the hole?

Re: Gear lube problems

That hole has nothing to do with the gearcase oil. The gearcase is sealed and you fill it from the bottom (drain) screw until it overflows the top (vent) screw hole. The little hole drains water/oil from the exhaust leg of the motor. Water and exhaust residue build up in there and the hole just allows a means to drain that leg.

Re: Gear lube problems

lindy46 said:

That hole has nothing to do with the gearcase oil. The gearcase is sealed and you fill it from the bottom (drain) screw until it overflows the top (vent) screw hole. The little hole drains water/oil from the exhaust leg of the motor. Water and exhaust residue build up in there and the hole just allows a means to drain that leg.

Click to expand...

Yep, you put oil in the gas and it goes through the engine with the gas. Some of it burns (smoke) and the rest goes out the exhaust. There it mixes with spent cooking water and emulsifies. What's left and doesn't go out the exhaust pipe will come out the various drain holes to worry you to death. Stop worrying about it.

Running the motor out of the water (or muffs) can melt the water pump.

Re: Gear lube problems

Water Pump Housing melted! To my knowledge, the only way that impeller housing can melt down is to have the inner exhaust housing extension missing which would allow the red hot exhaust beat directly on the water pump.

Re: Gear lube problems

F_R said:

Yep, you put oil in the gas and it goes through the engine with the gas. Some of it burns (smoke) and the rest goes out the exhaust. There it mixes with spent cooking water and emulsifies. What's left and doesn't go out the exhaust pipe will come out the various drain holes to worry you to death. Stop worrying about it.

Running the motor out of the water (or muffs) can melt the water pump.

Click to expand...

Wait, running the motor on muffs can damge/melt the water pump?? I've never heard that. Is that only if you run it at high RPM on muffs? Which I would never do with no load on the engine anyway....but just curious.

Thanks.

Re: Gear lube problems

Running a high hp engine using any type of flushette, you want the hose turned on full blast. Was that inner exhaust housing extension present when you inspected the water pump?

Re: Gear lube problems

Yeah, the gasket was blown out on the stern end of the motor though. I fixed the gasket, siliconed everything.

Today I dropped the lower unit--again, replaced ALL seals except the prop seal. I saw where the gear lube was coming from, below the water pump from the top bearing. I also noticed the shaft is bent somewhat because the top seal on the aluminum thingy with the two ports for the water pipes is egged, and the shaft sits a little to the side on it. Either way, found WHERE it's coming from, if the shaft is indeed bent (strange that it would be, rather I'd imagine the aluminum piece is bent) then I guess I'm screwed. Otherwise, I shouldn't see any more water in my gear oil.

I'll take it out tomorrow maybe and we'll see... if so, I don't think there's anything else I can do other than change the oil out every time.

Again, just seems strange that when I GOT the motor, the oil was black with no water present. And I'd guess the boat was owned by a moron at some point in time that ran it out of the water at high RPM to melt the housing.

Re: Gear lube problems

Well, took it out today. Ran great, but when I landed it and tilted the motor up... a bunch of clean water came out, then milky gear lube. I'm hopeless... guess I'll just have to buy lube in 5 gallon buckets and change it every time.

Re: Gear lube problems

(Checking Gearcase For Leaks)
(J.Reeves)

Remove the large slotted drain/fill screw from the bottom of the gearcase and also the identical looking screw that will be located up near the cavitation plate in order to drain the gearlube.

After all of the lubricant has drained, install one of the slotted screws, whichever your preference might be.

Apply 7 to 12 pounds of air pressure to the open screw hole. Use a piece of rubber fuel line or something to create a tight air hose fit if you do not have a proper fitting.

If a leak exists, that pressure should allow you to locate the leak by sound and/or sight.