Ant, my pump turns freeley by hand, no super easy but with mild effort. Try pulling up and down on shaft to see if it has any major play.Who else to call but jack at mpd in costa mesa...RA,RA,RA,RA. GIVE ME A M, GIVE ME A P, GIVE ME A D, CHET WAHT DOES THAT SPELL? Good luck with pump.
DANO