You're mowing with your riding lawn mower and it suddenly stops moving. The engine's running fine, and the mower blades are spinning, but the mower just won’t move. You wonder what's gone wrong. A cursory inspection reveals the transmission drive belt has come off. You do the necessary maneuvers to get it back in place and once again your mower will move. A few minutes later, the same problem happens. Now what should you do? This is one of the many frustrations of life, but can be remedied with a careful and conscientious following of suggestions in this article.