Lower unit oil change

[pabloescobedo96]

Hello, I have a 1979 35 Johnson outboard model# 35EL79A Serial# E5083405
I am changing the lower unit oil. It doesnt seem like it is taking much oil. Prolly 1/4 quart or less. Does this sound right? I am having a hard time telling if its full. I know to watch until it runs out the top hole but it runs out the whole time im trying to fill it. Also Is it ok to use regular automotive gear oil ?
Thanks

 

[CATransplant]

Re: Lower unit oil change

You have to fill the lower unit from the bottom hole. Remove both the top and bottom oil plugs. DO NOT REMOVE THE PHILLIPS HEAD SCREW! You can use one of the tubes of lower unit oil that screws into the bottom hole, or a pump unit that has a hole that screws into the bottom hole.

You can't use automotive gear oil. Buy outboard motor lower unit oil, which you can get at any marina, most sporting goods stores that sell boating stuff, or even Walmart. It has special properties that help hold any intruded water in suspension to protect the gears and bearings.

 

[pabloescobedo96]

Re: Lower unit oil change

You have to fill the lower unit from the bottom hole. Remove both the top and bottom oil plugs. DO NOT REMOVE THE PHILLIPS HEAD SCREW! You can use one of the tubes of lower unit oil that screws into the bottom hole, or a pump unit that has a hole that screws into the bottom hole.

You can't use automotive gear oil. Buy outboard motor lower unit oil, which you can get at any marina, most sporting goods stores that sell boating stuff, or even Walmart. It has special properties that help hold any intruded water in suspension to protect the gears and bearings.

Wow I'm a dummy. I assumed it was just like filling a rear end in a car. OK, so I will remove both plugs and force the lube into the lower hole until it comes out the top? Then put the plugs in fast.
"It has special properties that help hold any intruded water in suspension to protect the gears and bearings."
That is exactly the info I was looking for. Any idea how much lube this thing holds?

 

[CATransplant]

Re: Lower unit oil change

That's the idea. When it comes out of the top, screw the top plug in and tighten it. Then, remove the hose or tube screwed into the lower hole and insert the lower plug. Very little will run out, so it's not like you have to work too fast. Be sure to use new gaskets or o-rings for the plugs.

I don't know exactly how much it holds. The big tube of it will more than do it. I use a pump and buy the larger size container, since I do this from time to time on more than one outboard.

Either way works fine. Any marina will have the big squeeze tubes, as will the other places I mentioned.

 

[Mas]

Re: Lower unit oil change

After the oil starts coming out the top plug, plug the top hole with your finger. This will prevent the oil from easily flowing out the bottom because it creates a vacuum as it tries to ooze out. Once your lube oil pump is removed, just screw in the bottom plug. Make sure your use "new" plug washers...easy place for new leaks to from if you do not (not oil out, but water in!).

MAS

 

[samo_ott]

Re: Lower unit oil change

Buy the pump, it'll be the best $10 you ever spent if you change your LU oil more than once a year! And then get a 1 quart container and it will screw right in... Don't squeeze tubes, it'll make a mess...