Possible Cause: Belt is loose, damaged, or oily.
Corrective Action: Check belt for damage and proper tension. Replace belt if necessary
Possible Cause: Damaged or loose motor mount.
Corrective Action: Examine motor mount. Tighten any loose bolts.
Possible Cause: Fan speed is too high.
Corrective Action: Check system balance. Adjust sheaves or motor speed as required for proper airflow.
Possible Cause: Damaged or unbalanced wheel.
Corrective Action: Examine wheel for damage. Replace blower assembly.
Possible Cause: Damaged bearings or shaft.
Corrective Action: Examine shaft and bearings for damage. Damage to shaft or bearings requires replacement of blower assembly.