I just got a new wheel to replace my old (broken spoke, badly out of true and round rim without any tension applied). I got it replaced under warranty at Sports Authority (I know. Buy it at a real bike shop ) My old wheel had a no-name hub and rim. The new wheel has an Alex rim and a no-name hub. I feel a lot of friction on the hub when I spin the rear wheel without the gears (not sure if they're a cassette or freewheel). I assume this means the hub needs to be repacked?
Also, are the sprockets from the old wheel compatible with the new wheel (ie are they of the same type; freewheel or cassette)?
Edit: and yes in the last picture, that shiny part of the hub is threaded.
Edit 2: Oh and my old wheel is 7spd with a 3x7 drivetrain.