Not quite sure what you mean Russ- do you mean the stub that goes through the chainwheel/brake drum bearing, and that the main axle passes through...we are talking Plunger, hey?
If I assume so, I'll also assume you pressed on it with a nut on it and some kind of mandril- like a big bolt(was thinking the axle reversed, but that wouldn't fit..!)..? Only thing I can think of, (if it's what I'm thinking), is the stub may have 'welded' itself to the bearing- try soaking it in ATF and acetone...or heat the bearing...
Did you remove the bearing circlip, and bearing from the brake drum/chainwheel ?