Whrilpool Dishwasher diffuser leaking

Hello, I’ve had this dishwasher for just over 1.5 years now. It was periodically leaking but would always seem to "fix" itself when we would have a repair guy come out during the warranty period. Since then it has started leaking regularly.

Here’s what I found…
The leak is happening in the shaft of the motor/gear assembly that turns the diffuser. I pulled the unit out and removed the pump assembly and everything. I tried to put an 1/4 inch o-ring on the shaft of the motor on top of the original seal, but that seems to have just made the issue worse. Is there anything that I can do? I can replace the original seal, but it doesn’t appear on any of the parts breakdowns that I’ve seen.

Thanks for your help.