Maytag designed the belts to run very loose compared to other models. Probably one of the many reasons why their pumps last for several decades. The official test:
Grab the motor and firmly pull the entire carriage assembly back. Pinch the pump belt dead center. You should feel the motor just begin to move when there's 1/4 inch distance between the pinched belt. If not, loosen the 3 pump screws and adjust accordingly. (Why do I get the feeling of a slap coming from RDC.....LOL!!)