My Previous Post Earlier Tonight Was For A Grinding Noise...i Have Determined It Is A Loose Impeller. How Do You Keep The Motor Shaft From Turning While You Unscrew The Bolt That Retains The Impeller. The Impeller Seems Stripped And Does Not Engage To Hold Anything Tight Using The One Inch Nut Cast Into The Top Of The Impeller. The Entire Impeller Rocks Back And Forth And Can Spin Freely Without Engaging The Motor Shaft... So It Might Appear That I Have To Find Some Way To Lock The Motor Shaft To Unscrew The Bolt To Remove The Impeller. Any Suggestions?

Thank you for the advice on jamming the motor fan. The dishwasher is still installed under the counter and I couldn't initially get to the fan. I finally was able to jam a bent allen head wrench into the fan from the bottom side of the motor and remove the impeller bolt and broken impeller pieces. Hopefully all will go back together and work.
Thank you again.
RSC