Be sure all pulleys are designed for, and correct for the same V belt. I'm guessing they are. I once had a belt problem years ago when a clerk at the local parts store sold me a V belt which was designed for a different size pulley (smaller) because "my belt was not in stock, but this one was" The belt I was sold was thiner for a smaller type Sheave (pulley) After about a month, it literally was hanging on by only the thin strip of metal which was in the center of the original belt. The reason? because it was thinner, it rode deeper on the sheave, and was force to turn at a radius tighter than it was designed for, resulting in its destruction in a very short time. Good luck.