So as per the other thread, I successfully removed both rear calipers and am continuing the job of cleaning up the rest of the rear brake system (prop. valves/hoses/lines/rotors, etc.). But now with both discs off, I just want to confirm that my bearings aren't bad. When I rotate the hubs I can hear a muted "click" like the sound of a hockey card in bicycle spokes but obviously dulled and coming from the axle or differential. Is it just the differential gears, or could it be the bearings? Should the rear hubs spin silently like in the front? What should I be listening for to identify a bad bearing?

As others have suggested, I don't want to fix what's not broken. But if there is an issue with the bearings it's probably as good a time as any to get in there. That said, the mounting bolts are as corroded or more so than the caliper bolts, and I don't believe they've ever been removed. So I don't want to push my luck if it isn't necessary.

Again, I apologize for being the noob of the century here, but seeking guidance (and offering where I can) is why I'm here. Thanks everyone.