I have a whirlpool dishwasher. It quit working today. I just took it apart, and I can see that the impeller blades are all missing. I can't tell if they were knocked off, or eaten away. There seem to be no pieces floating around inside, and the motor is working.

No leaks.

So, I see that impellers are only, like, $20.

2 questions:
1) How do I get the darned thing off the motor shaft?
2) I see the impellers (PN: 3108052) are out of stock - how soon can they be delivered if I order now?
3) (I can't count) - what else should I get to ensure the repair is good?

This is just a forum sponsored by AppliancePartsPros, you should email or phone them for an ETA on the parts you need.

I was looking for info for you but could not find anything decent on pump repair but perhaps the following will be of some use.
https://secured.whirlpoo...510938/$FILE/4322430.pdf

As to what happened I can only guess. Something could have got in there, ate up the fins and then once they were gone was able to get out.
I would check the drain assembly just in case it is now stuck in there.