Opener runs but makes loud grinding or rattling noises during operation.

Safety first: Disconnect power before tightening hardware or working near moving parts. Do not place hands near the chain or belt while operating.

Steps to reduce noise:

• 1. Inspect chain or belt: For chain-drive models, check sag at mid-span. Adjust tension so there is about 1/4 inch of sag. For belt-drive, follow Stanley’s specified tension procedure.
• 2. Tighten hardware: Check all rail-to-opener bolts, header bracket bolts, and hanging straps. Tighten any loose fasteners.
• 3. Lubricate door hardware: Apply garage door lubricant to rollers, hinges, and springs (do not over-spray springs). Do not lubricate the opener rail if it uses a belt; for chain-drive, a light application of chain lubricant is sufficient.
• 4. Inspect sprockets and pulleys: Look for wobbling sprockets or worn idler pulleys. Replace any visibly worn components with Stanley-compatible parts.