Hmm... From the reading I have done I see that the fluid used in those drive units is the same for the transaxle in front so it is ATF and pretty thin. That would make sense since the rotor would get bogged down with a heavier weight gear oil.
Check these out...
Electric Oil Feed and Scavenge Pumps It would save a lot of headaches trying to rig belt or chain drives for a pump. They could be set up to activate when the drive unit got over a certain temperature.
Cyruscosmo