gear oil

[fakeplay]

Please learn me on how to fill the lower unit with gear oil. The book say's fill to vent hole thru the drain plug in a vertical position. NOW HOW THE HELL ARE YOU SPOSE TO DO THAT WHEN THE VET HOLE IS ON TOP ? sorry bout yelling.
Won't the lube drain out of the drain plug ? Before I have a chance to close them ?

 

[CATransplant]

Re: gear oil

What engine are you filling?

Anyhow, most outboards have two plugs, one near the top of the gearcase and the other near the bottom. To drain, you remove both plugs, with the outboard upright.

To fill, you press or screw the fill hose into the lower plug and pump or squeeze the lubricant through that hole into the gearcase until it comes out of the top (vent) hole. Then, with the hose or tube still attached, you screw in the upper plug. Then, you can either lay the outboard on its side and re-install the lower plug or just remove the tube or hose and quickly install the lower plug (that's how most of us do it.) Very little gear oil will escape.

If your gearcase has just one plug, you drain with the plug down and fill with the plug up. Can't do it on the transom, but such outboards are small and lightweight.

More questions? Ask away.

 

[JB]

Re: gear oil

Excellent explanation, CAT.

The reasons we do it that way is because the oil/grease is so thick that if we filled from the top we would get air pockets. That would be very bad.

By pushing it in from the bottom all the air is forced (vented) out the top hole and we have truly full gearcase.

If we put the vent plug back in before we remove the filler the oil can't drain because there is no way to get air in above it.

Yes, it is a new experience for most of us, but thick (90W) oil just doesn't behave like water would.

 

[fakeplay]

Re: gear oil

OOHHHHH, now I get it ! Thanks