We hoped to get on the road today, but it starting snowing just as we went outside to work.
We still wanted to do *something*, so we set up my propane heater pointed under the bed and cracked open the diff. Surprisingly, the fluid came out honey golden.
The gears look good, no play anywhere. So we scraped out the rest of the oil, wiped it down, put it back together with a new gasket and refilled it.
One step closer to being on the road.