Since I last posted, I've clicked the axle back in and refilled the oil level. I suspect it wasn't fully clicked in the first time.

The differential that is pictured in the first post was not in my car. As you can imagine, that one would not have functioned in any way.

The diff that was in my car didn't make much noise except mild clunking at times, and oil seeping from the oil seal. On teardown, I found 2 significant problems: 1) the drivers side inner CV had a snap ring bent and out of place, and 2) the diff bearings were spalled. The axle play and oil leakage is what really had me suspicious.

Dave