there is probably a burr on the inside of the hub that is holding it back, just give it a little tap in with a hammer and see if there is come crap holding it up, here is a picture of a new one so you can see that there is nothing holding it. those lock rings just retain the hub and bearings
you can also google warn hubs and find a lot of info. if people serviced their front hubs more often they wouldn't have any problems
ron