Product review (5 stars): Worth the Effort to Replace Belt
Dishwasher would not drain completely.  Rather than removing parts to see whether there was a partial blockage, I decided to just replace the belt which seemed a little stretched.  The old belt came off a lot easier than the new one went on, but now my dishwasher drains completely and cleans better.  Real pain to put the new belt on, but well worth it.  Amazon offered a better price and faster delivery than several appliance repair parts companies.