Lower unit oil change w/full synthetic

[gss036]

I just put my boat up until at least Feburary, so figured it was a good time to change the lube in the lower units. 1989 Mercury 200 HP and a 1995 Honda 15 HP. It was about 45 degree w/sun out, but I could not believe how long it took for the oil to drain. Definately had the smell of gear oil and looked to be about 90Weight. I didn't put this in, last time in the shop a couple years ago the guy checked and it has water in it and he pressured tested and changed the seals and put in new oil. The oil looked good no water and no metal shavings,WHEW !!!! that was good.
Replaced it w/ 75-90 wt full synthetic lower unit oil by LuberMatic(?) . Now I can relax and not worry about the cold winter. I would think this is acceptable lube, expensive enough at about $11.00 qt.

 

[Chris1956]

Re: Lower unit oil change w/full synthetic

I think it would be better to change it at least once a season. Your writeup implies you left the gear lube in,over the winter, after a season of usage. If water had gotten in, it might have cracked the gearcase.

I also do not think that that LU requires full synthetic, since it was not invented in 1989.

 

[gss036]

Re: Lower unit oil change w/full synthetic

I agree with you there, just oversight, maybe because I put less the 50 hours a year on the 200 now with our short season. Our colder months can be Feb/March and I do use the boat then weather permitting. Just use my Mustang cold weather gear ( same as the C/G uses). No, I don't think it requires synthetic, but that seems to be trend these days and I had 1 1/2 qts sitting on the shelf in the unheated shop, which is where the boat is kept.

 

[Texasmark]

Re: Lower unit oil change w/full synthetic

Agree with Chris on water and winter don't mix. I have syn in mine too. Why? I'm asking myself that but right now have no response. Just did.

Mark

 

[Bondo]

Re: Lower unit oil change w/full synthetic

Ayuh,...........

I fill All of them with Mobil 1, 75W-90.......

Even my old 1954 Johnson 5, 1/2hp........

 

[gss036]

Re: Lower unit oil change w/full synthetic

Glad to hear all the comments. I was wondering about the 75-90 instead of straight 90 wt.
I got 2 small plastic washers from the Honda shop for the 15hp. $1.83 including tax. You can a pack of 5 for the Mercury for about $1.75. That has always been the story on the Honda, all the parts are 3 times as much.

 

[Outsider]

Re: Lower unit oil change w/full synthetic

.. since it was not invented in 1989.


AMSOIL gear lube has been around since the 70's. It was just as good back then, too ...

 

[pecheux]

Re: Lower unit oil change w/full synthetic

Have 2 OB's I use Amsoil (not that it matters) synthetic oil in the gearcase of my 15 hp Force mainly because it contains less oil than my 9.9 Johnson (and of most ob's) so I want to compensate with more lubrification (I think)

The Johnson gets the Merc HD gear lube because I have a good quantity of it and it needs to be used somewhere ... LOL

 

[jspringator]

Re: Lower unit oil change w/full synthetic

Our local Wal-Marts no longer carry Pennzoil synthetic outdrive oil, but they do carry their house brand synthetic gear oil, which is SAE 75w-140, API GL5. Will this be OK on my 25 HP Evinrude? Looks like 75 weight oil with additives to make it 140 under certain conditions. All the others mentioned don't go that heavy.

 

[Texasmark]

Re: Lower unit oil change w/full synthetic

You probably will never see the temp that the 140 rating is provided for. What you probably really want to know is what is the (relative) viscosity at the water temp you run in.

If I knew I'd tell you as I have wondered that myself in other applications.

Mark