Felt some vibe in the right rear again this weekend so decided to pull that axle and have a look. Plenty of play in there so I'll replace the bearings and seals for sure, and clean out all the old grease and muck.
There appeared to actually be some moisture mixing with the grease though, enough to have a little bit of "dirty water drip" come out when I removed the axle assembly. It was 42-year-old nastiness in there for sure. The car has been garage-kept for almost 10 years, should I be concerned about the oily-grease muck?
You may recall I replaced the busted drivers side bearing a few years ago, but no muck on that side at the time.