auger won't drive. Found a broken plastic drive cup,
ordered a new one, installed, and it broke again. Auger
seems to turn pretty freely by hand.

one more thing - after installing the new cup it worked for a
few days, but today it jammed, i forced (not hard! really! barely turned
it) the auger to drive a little, and then noticed the large white disk
from the front end of auger assembly had slipped back about half way
down the shaft towards the rear.

not sure what to try next! another plastic cup and make sure the auger
is properly assembled this time?