GE dishwasher lower impeller doesnt fit correctly

[shaggybob2k]

Model Number: GSS1800H00BB
Brand: GE
Age: 6-10 years

I recently had to replace the lower impeller as its collar was broken- I ordered the correct part number and it matches the old P/N. Problem is it doesnt mount flush to the seal assembly and causes the drain cover to leak. The motor reverses and the impeller spins, but doesn't seat low enough to allow the drain cover to fit properyl. The collar on the impeller fits on the motor shaft fine, the plastic ring that is supposed to be on the seal assembly that fits around the motor shaft is up to high-I though it may be the old collar from the broken impeller but its not. Any help would be appreciated as this is a simple repair. or so it would seem. GE swears the part is the one that came with the original washer. I'm pretty good at mechanical repairs so I'm just really stumped on this one.

[Doc Ryan]

Did you compare the new part to the old one to see if they looked the same?

It sounds like either the impeller is defective or there is another part broken somewhere in the pump causing it not to fit properly. Why do you think the original collar broke on the impeller in the first place? That might be the cause of your problem.