I have an older Maytag model that will not spin. It started out as a weak spin. I took off the tub and checked the hose and everything looks fine. Also, took off the pulley and belt, cleaned everything up and checked the thrust bearing. The bearing appears to be moving without friction and the cam is not worn down. The problem is that the brake appears to be stuck on. When I rotate the pulley CW it moves the agitator. When I move the pulley CCW it still moves the agitator. If I force the cam to separate with a screwdriver it will loosen up the brake. however when the cam closes again it will not move freely enough to release the brake. So, in other words, there appears to be too much downward pressure on the cam, not allowing it to move freely. I even took out the washer on the bottom of the shaft to free up some space. still nothing.
Here is the Service manual.
Here are the breakdown diagrams and http://www.appliancepartspros.com/partsearch/model.aspx?model_id=46530
Gene.