Zanussi aquacycle 1050 FLS 1183W won’t drain

I thought i may have found a similar topic but i’d like to confirm my drain pump motor definitely needs replacing:
post134319.html?hilit=askoll#p134319

The machine used to make a horrible noise when draining but still worked ok. Last week the horrible noise turned into a rattle and the machine doesn’t empty any more.

I’ve taken off the back, unscrewed and removed the pump. The impeller wasn’t attached. 180ohms across the terminals. I put the impeller back on and tested the motor with it positioned completely out of the machine. The motor turned ok (however the impeller whizzed off across the kitchen).

Having read other posts i understand the motor can spin either way. Also that looking at the end of the shaft it isn’t tightly coupled to the impeller and can move 1/2 turn without the impeller turning – this sort of ties in with the a post (think it was by penguin45) saying resistance should be felt and then the impeller “pings” twice(?) per full revolution. It intrigues me why the impeller isn’t tightly bound to the shaft- there must be some design reason for this?

Anyway my main question is…
The shaft of the motor also moves in and out – is that supposed to happen?

There are some spacers packing out the shaft before the metal end that mates with the impeller but not enough to stop it moving back and forth. As they are plastic it seems like it could have lost one which has introduced the play on the shaft and hence the impeller flying off and rattling around in the chamber instead of draining. Also even if there wasn’t any play in the shaft i can’t actually see what prevents the impeller falling off- does it butt up against something when fitted?

Any help will be much appreciated.

Cheers,
Ian