There has been a whirling sound coming from my front left wheel for a couple of months now. The mechanic said the wheel bearing needs replacement. But, he also mentioned the wheel could separate. I know the bearing is pressed into the hub, is it possible for the wheel to come off?

 

if it gets very bad. The bearing is sandwiched between the hub and the outboard axle joint. so if the bearing gets so bad the wheel may not come off but it may bind and not want to turn anymore.