This usually turns out to be a stripped wash impeller or at the very least a piece of debris caught down where it should not be, in the lower wash impeller. Maytag has developed a stronger impeller for this model that resists breakage and has a metal shaft instead of the plastic one it came with originally. The
impeller chopper and sleeve kit is pictured below and you may use your correct model number to order it. Instructions included in the kit.

Any repair questions can usually be answered by referring to the
Maytag Dishwasher Service Manual. I usually find a small piece of something down in the depths of the pump after a little disassembly. The tiniest debris can sound like a Peterbilt in these flimsy plastic pumps. You may just find that a thorough cleaning takes care of the problem.