Filling lower unit with oil...

[Dan21XRS]

I'll write it down this time... 4-Stroke 115 with Command Thrust... SN B224433... Do I fill to the top and let a few ounces escape before re-installing the screw, or do I fill to the bottom of the vent screw and then re-install the fill screw without letting any oil escape... Have 2 different lower unit, trying to remember can drive an old man crazy... Dan

[Mechanic Bob]

I have always filled it from the bottom.
I took an old metal sprayer. (Those used for spraying your lawn or garden with pesticides.) Fitted it with ball shutoff valve, clear hose, and the fitting for the lower unit. Pump it up, open the valve, and wait for the lube to come out the top hole. Close the valve, turn the prop by hand to clear any trapped bubbles, open the valve, close valve when lube comes out the top hole. Put screw with new seal back in the top hole. Then remove the rig and install the bottom screw with a new seal.
This way the lower unit is not over filled and not pressurized.

[G4bama]

I have the same engine and I pump mine in from the bottom. When oil runs out of the vent hole, I stop pumping. I then slowly turn the prop to bust up air bubbles and will let it sit for a few minutes. Give it a few more pumps till it runs out then call it good. The book says that the gear case holds 27oz. I got 23oz in mine. Good to Go

[Erie660]

Pump from the bottom until it comes out the vent hole, then put the vent screw back in first and then the drain screw.

[Skeeterbait]

Pump from the bottom until it comes out the vent hole, then put the vent screw back in first and then the drain screw.

This. Don't over think it.

[EuropeanAM]

Pump from the bottom until it comes out the vent hole, then put the vent screw back in first and then the drain screw.

+2

And not "still spewing out of the vent hole". Proper level is AT the bottom of the threads of the vent hole.

[vandamit]

is it okay if a little gets out the drain hole before you can get the plug back in?

[Mechanic Bob]

is it okay if a little gets out the drain hole before you can get the plug back in?

Yes.

[Ches.]

I have never even thought about rotating the shaft. I just trim to level, drain lower unit (a little past horizontal), fill till it starts to come out vent, put vent screw in, remove filler tube and put in fill screw. That's it. fluid came out looking like new yesterday.

[EuropeanAM]

is it okay if a little gets out the drain hole before you can get the plug back in?

A few drops: Yes. No more than .5 (1/2) ounce on this particular gearcase.