Usually indicates a loose belt or a seized idler pulley.
Look for "cracking" on the back of the belt or "root wear" at the base of the teeth. 28inchesp322432s028rzip
Most belts of this grade should be replaced every 60,000 to 100,000 miles (automotive) or 20,000 run-hours (industrial). Troubleshooting Common Issues Usually indicates a loose belt or a seized idler pulley