if the machine fills to the set level and the motor is running
to agitate check underneath and see if the large center transmission
pulley is turning. If it is and the agitator isn't going back and forth then
you have a bad transmission...time to buy another machine.
If the large pulley isnt turning but the motor is running then the belt is slipping on the motor pulley.
Those plastic motor pulley go bad and melt as you described and may be your problem, and if so,
you can't buy the "exact" replacement pulley w/o buying the motor...but, the is another belt and
pulley combination that can be used if you find that this is your problem.
Let us know.
Source: re: Maytag MAV 5000AWW