I usually end up installing a stud and nut in the topmost hole of the axle housing - which not only allows me to control the cover when I'm draining things, but also helps me to line everything up with rather less wrestling when I close. Hang the cover and gasket on the stud, start the bottom screw, then start the rest. Problem solved - and easier to do with only two hands (I'll usually put studs on valve covers, oil sumps and transmission sumps when I remove them for similar reasons. Even though they're not maintenance items, it saves much wrestling and use of evil words...)