Sounds like a thermal overload. Is the motor hot to the touch? I had two 3-4 year old Whirlpool yesterday where the inner basket was rubbing the outer plastic basket/tub on the bottom and was sagging. I spent quite a time till I figured out this was the cause. Installed two seperate trannies, clutch, brakes, etc. First time I have ever came across this issue whith Whirlpools. If you grab the inner basket and pull up there should be little if no play/give. If it is dragging, you will have slow spin or an overheated/thermal overload issue.