If you notice the level of the filler plug on the rear cover, it's slightly above the bottom of the axle tubes. That allows a small amount of the lube to run over to both axle bearings and keep them lubricated as well as the side carrier bearings and the differential gears. The spinning action of the ring gear throws the lube forward to bathe the pinion gear and both pinion bearings in oil as the vehicle runs- - -there's even a groove cast into the center housing for the lubricant to follow as it moves forward above the pinion gear. The ring gear makes a very efficient lubricant pump- - - -I even used to drill and tap a forward-facing thread for a pipe fitting into that upper channel to use as a passage for rear axle lube to be pushed forward through flexible lines to a frame-mounted cooler on the round track race cars I built, using nothing but the spin-off from the ring gear as a pump. The cooled lube returned to the top of the left axle tube through another flex line.
Jerry



"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!