From what I've read here it sounds like one front drum came off and one didn't. You pictured the swaged studs on the one that won't come apart it appears. Can you show us what the side that came apart looks like? Just curious is all. Like the guys said, pop the hub nut cap, pull the cotter key, spin off the nut and pull off the drum and hub assembly. You can get in there to clean and inspect. You might need to clean and repack those wheel bearings that you won't see if you just pull the drum only.
