The BEST Outboard Lower Unit Oil

This is how to change the lower unit gear oil in an Evinrude or Johnson outboard. We haven't checked or changed the lower unit gear oil in this outboard since we replaced the lower unit oil seals. These tips will help make sure water stays OUT of your outboard lower unit. SUPPLIES ↓↓↓↓

Marine Gear Oil:

Vent/Drain Plug Gaskets:
 
****You need 2 seals. One for the vent and one for the drain. Most come in packs with a couple of seals. Most of the seals are the same for many different brands of outboards. Some of the vent/drain plugs use o-ring seals instead.****

****The paper gasket type sealing washers are not good. They are one time use, crush, leak, fall apart, and don't seal well. I ONLY use the plastic sealing washers: SIERRA Part Number: 18-4248 or OMC Part Number: 311598. The plastic sealing washers literally last for YEARS!****

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[MattsShop]

Chill guys!! I was in a hurry. You fill it from the BOTTOM so no air gets trapped.
Oil:


Vent/Drain Plug Gaskets:

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[svbarryduckworth]

We change our lower unit oil every six months when we also change the crankcase oil on our tiny Honda 2.3HP. I also drain the onboard tank to check for any water and inspect the in-tank fuel filter.

This outboard is out daily driver and sometimes takes 3 round trips a day between our sailboat on anchor and shore. When I tried to stretch it to a year on the lower unit it didn't smell too good at change time although it still looked clean with no water.

It only takes .05 quarts of LU gear oil so that is a 20 oil changes with no spillages on one quart so oil cost isn't so much of a big deal. I let a bunch flow through and out the top hole when I fill from the BOTTOM hole to flush it a bit so I probably only get 10 changes out of a quart of the oil.

Fill from the bottom until it flows out the top then leave the hose connected at the bottom while screwing the top plug back in. The oil is thick enough so when the top plug is in no air can get back in and nothing drips from the bottom plug when the fill hose is unscrewed -not much more than a drop.or two at the most.

If you fill from the top there is a good possibility that an air pocket forms near the bottom and you will underfill the LU which will leave you with a low oil level once that air migrates to the top when it is run the first time.

[petersallander]

Should fill from the bottom up to get all oil out.

[AaronGoSoFast]

He makes a good point. If you're gonna change the oil anyway then the cheap stuff should suffice. Plus the premium shit, costing around 5 or 10 times more, doesn't necessarily provide 5 or 10 times better protection. Probably closer to 1.1 times better protection, but only long term. Short term, probably no real benefit. Unless you have money just flying out of your ass the less expensive stuff is much more cost effective.

[johnellenburg]

He just filled from the top .thats not right

[stevemoeller]

Buddy
From the video it looks like you had very little oil in your lower unit flow
And you dont pump the new oil in from the top. There would be an air lock and not allow you to fill the gear case properly

Hope you havent damaged your gears😮

[floroy]

Hey dude the seal screw with the magnet goes in the bottom, it collects metal particulate from the oil, the metal particles cause premature wear on gears and seals👍🇨🇦

[sezwo]

Yes, it is a preferred strategy for engine longevity to change more often with a cheaper but still within specs oil than to use a more expensive oil and not change as often. Extended drain intervals are hype in most cases. Good for the manufacturer but not as much for the consumer. After a long extended drain interval the small amount of oil that remains in the engine after an oil change (can be 1/2 to a quart for car/truck engines) is so dirty it immediately compromises the new oil! This necessitates a double change. Fancy oil manufacturers say their oil is good for 10k or some even say 20k and it may be true of the oil itself but the practice it is not necessarily good for the engine as not all of the oil can be evacuated during the oil change, ...and no one wants to introduce a significant amount-10 percent or more, of old super dirty oil into the new fluid.

[nunomascarenhasribeiro]

All good…but fill from the bottom until leaks on top without air bubbles….

[abeham]

Is it ok to use 80w 90 oil on a Omc 3 liter drive for the lower unit?

[andrewshoemaker]

Should there be a plastic washer on the bottom plug. I took mine off and there wasn’t one.

[alecfed]

All the other guys say you fill it from the bottom until it comes out the top, does it matter?

[criagwade]

Guess who want be doing anything to my outboard

[criagwade]

So I'm not sure this young man know much about what he's doing! Always fill from bottom. Always use best not cheapest replacement oil.

[tcbiglake]

Ya use whatever oil and change it often…. But … uh ya…. I haven’t changed it since 2016…. Um … uh …. Follow me for more tips lol

[Harrell]

Pennzoil sucks in my opinion. Then you kept talking and it all made since lol