I was when changing lower unit oil you are supposed to pump it in from the bottom drain hole Via an adapter that screws into the threads. You then pump the oil in and it gets in the lower unit and fills all the voids better than pouring in from the top. We usually have poured in from the top, and it has been fine for us so far. Have I been out of the "loop" and not heard about this new or old technique, or is it not a true statement?
Please inform me on this subject, thanks
AC

The prefered method is to use the $7 adapter. That way you are sure that you have removed all air from the lower unit cavity. By pouring it in you have no way of knowing how much air is in the case.

With gear lube being so thick coming from the bottom you are assured of not leaving any voids or air pockets. Going from top like you say can work but it is a little more time consuming waiting for the lube to settle then adding more and waiting to make sure it has settled with out air pockets.

With the lower unit in the down position or level, fill from the bottom until it comes out the top.

Thanks for all the quick responses. Guess We'll have to get one of those adapters. Good to know though.
AC