Right rear sticking

I wouldn't doubt that u had an ongoing brake problem and just never noticed because the puked axle seal kept the shoes greased up and not working at all! Or even that ur wheel cylinder locked up a long time ago and over heated things causing the seal to leak. Like has already been said, push the wheel cylinder back and forth by hand, as u push one side in the other should push out, almost as if they were one piece, and it should be relatively easy.