Almost every Walmart in the USA carries Quicksilver High Performance 90W Gear Lube in the boating section. It is made by Mercury for the lower unit of marine engines. Bet they carry it in Canada, too. That's what I use in my SM420 and my Eaton HO52 rear end.
Thanks Maybellene; Looks like I can get it at Canadian Tire over here. I will look into that. One thing I have noticed is the packaging seems to differ as to which side of the boarder its being sold
Mark