TOPIC: 65 merc lower unit oil

gonna change the lube in my lower unit...already drained...anyone have a refilling procedure?

fill it from the bottom hole up. When it comes out the top vent hole you are full. Close the top vent screw then put the bottom fil screw back in place. Keep an old coffee can or something under the lower unit to catch any oil that might drip then clean off with a rag.

Is motor down in normal opperating position or tilted up in travel position? does it matter?

DOWN!

thanx guys...i have never poured UPHILL b4 lol...just kidding, i have a small transfer pump so off i go. was advized to pressure test it to..10-15 psi.

Ok…the motor is down. I know it was a stupid question. However I was looking at an old Merc manual the other day. They described this procedure and the photo had the motor tilted up. I thought have I been doing it wrong? So I asked.

While on this topic and Delirious mentioned pouring oil UP. If you fill from the top until oil comes out seems like an easier plan then filling from the bottom until oil comes out the top vent and trying to rreplace the plugs. I suppose an air bubble or a internal obstruction could interfere with a complete filling of the chamber if pouring from the top. But it really seems like doing it the hard way.

you fill the gear case from the bottom. Squeeze the tube or buy a quart bottle of gear lube and get a pump attachment. Fill it until oil comes out of the vent screw. DO NOT fill from the top down. Do it with the motor in the down (running) position. You not want to run the gears without enough oil it will get very expensive quick.
Good Luck

Some of us antique outboard collectors make a gear lube pump from a two gallon lawn and garden sprayer like this one with a different tip. www.menards.com/main/lawn-garden/lawn-plant-care/biologic-2-gallon-handheld-tank-sprayer/p-1768594-c-10116.htm

If you fill from the top down, the oil will start running out right away. If you put the lower plug in then, you will not fill the unit completely, with a big air pocket in it. It has to be filled from the bottom up to make sure it is full. When it is full and you put the top plug, it forms a partial vacuum and the oil pretty much stays in place until you get the bottom plug in. Just wipe off what dribbles out and you are ready to go!!
Bill