Is the hub off the truck? The outer wheel bearing is contained in that hub extension (top hat) with the wheel studs in it, which is what I assume you're trying to separate from the drum. If the hub is still on the spindle, the outer wheel bearing and the spindle nut is what's holding it on. If the hub is already off the truck, disregard all the above!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!