I have a Whirlpool washer that broke the plastic drive connector on the motor. I replaced it and on the first load the replacement connector rounded off on the motor shaft during the spin cycle.

With the motor out of the washer, I can easily turn the transmission shaft counter-clockwise by hand and make the agitator work. However, when I try to turn the shaft clockwise I encounter strong resistance. I'm guessing that if that resistance is not normal it is the cause of the connectors failing. I would appreciate suggestions as to what might be causing the connector to fail.