I've gone and confused myself so I'm looking for a little help.

The left front wheel bearings on my daughter's '98 4WD 5-speed had some play in it. Having perused the forum I'm aware that sometime this just means the spindle nut isn't torqued correctly. So I figured I'd pull, inspect, re-grease and (assuming the bearings were in good shape) re-install the bearings. So I get all the way to the point that I've used the Ford spindle nut socket (with 2 of the teeth ground off) to remove the spindle nut. The hub assembly will not come off the shaft. In addition, the spline shaft that the locking hub mates to has about 1/4" up and down play in it (is this normal?). It appears I should just be able to pull the brake rotor and the hub should slide off the shaft. Unable to pull the spindle off the shaft, I tightened up the spindle nut/plate so that the wheel spun freely, but that there was no play in the bearing and bolted everything back together.

So what am I missing? Once the spindle nut/lock plate has been unscrewed off the shaft, what would keep the wheel hub from just sliding off the shaft?

Thanks for your guidance.