Lower unit lube

[LORDY611]

I recently bought a boat with a 1989 Johnson 30, and not knowing it's history went to change the oil in the lower unit. I opened both plugs and only about 3 oz came out. It was almost olive green, and not transparent like new gear oil. Assuming the previous owner filled it correctly, where could 10-12 oz of oil go?
Related question: where can the drain/fill plugs and or gaskets be found other than an OMC shop? (none nearby).

Thanks in advance for your time.

 

[rickdb1boat]

Re: Lower unit lube

Don't know where it went, but as long as there was no water in the fluid, it should be ok outside of being low. Try NAPA auto parts for the seals. Fill from the bottom until it comes out the vent....

 

[KYHunter2]

Re: Lower unit lube

As Rick instructed , to refill.

A good guess, as to where the missing fluid went.

Would be improper refilling procedure.

Meaning, it was probably never filled to begin with.

KYHunter

 

[OptsyEagle]

Re: Lower unit lube

I changed my gear lube two weeks ago and the oil my dealer had put in last year was a kind of dark green color. I enquired about it on a different forum and a poster told me that he thought it was most likely "Mercury High Performance Gear Lube".

I had not seen it before and like you was curious. I guess the stuff also comes in green.

 

[LORDY611]

Re: Lower unit lube

I am completely familar with the procedure from 20 years of doing 2 motors each year. I have just never seen so little come out before. I guess I am relieved (so far) that no one has said that the oil is leaking out the prop shaft seal, or something like that...

 

[rickdb1boat]

Re: Lower unit lube

If the oil was leaking out, water would surely be getting in. I'd filler up and see how she does. Didn't mean to insinuate that you didn't know what you were doing, but sometimes it's hard to tell from here if those you are advising have experience with outboards or not. Better to be safe....

 

[KYHunter2]

Re: Lower unit lube

As Rick stated, hard to know.

I was referring to the info. in your post , mainly :

"not knowing it's history went to change the oil in the lower unit."

No offence, intended.

It comes in different colors, but they all have a milky appearance ( not translucent), if you add water.

KYHunter

 

[LORDY611]

Re: Lower unit lube

see below

 

[LORDY611]

Re: Lower unit lube

It takes a little more than a few words about an outboard to get to me, so dont worry.
It has occured since reading some other posts that all gear lube may not be created equal, and that includes its appearance. I suppose that this stuff may have actually started life this color, but I doubt it. It came out a little slowly, meaning to me that it had become thicker with age and use. The odd thing about the situation is how immaculate the rest of the motor appears. While no trailer queen, you could eat off this motor. Just not beat up at all and everything about it shows good maintenance practices. The absence of lower unit oil sends up a red flag to me that the oil is going somewhere, and not that it wasnt filled up before.
So as recommended above, I have filled and sealed the gearcase and will try and recheck, with optimism.

Thanks to everyone who offered advice. I appreciate your assistance.

 

[Scaaty]

Re: Lower unit lube

Fill it up and use it. I just bought a new (old-like new 79 15hp Johhny), and it has slow green stuff in it too...normal. I've seen MANY a gearcase come by me that had little or none in the way of oil in them. Who knows what people do. I've seen air pressure changes blow oil out of the seals. Your fine....gearcases can take a little water anyway, and a lot of abuse. Just use it in the water for a good couple hours, then pull the bottom plug a touch and take a few drops as a sample. If its milky, ya need a couple cheap seals.