Yep, the hub was taper fit with splines that cut into the axle with a keyway and castle nut and cutter pin, most of the time when the key sheared off it would ruin the hub and axle when it spun, people would replace the key and torque them back on but they weren't stout after that, I've seen some welded, a lot of the jeep guys used to weld them, but nowadays you can get 1 piece axles to replace them. Like Rob said it takes a special puller to remove them, I made one years ago out of a slide hammer and torched out a piece of steel, but it was actually for a old 56 dodge truck, 8.75 rear ends were the same way in the 50's and early 60's.
