Does it really matter what condition the gears are in? Its the carrier/axle bearings that are really in play here? I would have to decide whether to run axle first time after 20? yrs to operating temp, and then immediately drain it, or do it before moving. Changing lube regardless would be a must for me.

Just dawned on me, there is no easy way to change the OEM 8.75 lube. Good luck.