If the drum is is tight to turn by hand it is possible that a small item child's sock etc has slipped in between front lip of stainless inner drum and door seal.This then gets caught between outer plastic tub and inner drum.It may be visible if u push back the door seal otherwise remove sump hose or worst of all remove heater add use wire coat hanger to pull out offending article.Good luck.
Lefty, September 2009