Decko garage door opener makes loud grinding or rattling noises during operation.

Safety first: Keep clear of moving parts while testing. Disconnect power before tightening hardware.

Check chain/belt tension:

• Inspect the drive chain or belt along the rail. It should have a slight sag (about 1/4–1/2 inch).
• Use the tension adjustment nut at the trolley end to tighten a loose chain/belt. Do not overtighten; this can damage the motor and sprocket.

Tighten rail and opener hardware:

• Verify that the rail is firmly bolted to the opener head and the header bracket above the door.
• Tighten all lag screws securing the opener to the ceiling and the header bracket to the wall.

Lubricate door hardware:

• Apply garage-door-rated lubricant to metal rollers, hinges, and the torsion spring (lightly).
• Do not lubricate the belt; for chain drive, a light application on the chain is acceptable.

If grinding persists and you see plastic shavings inside the opener, the internal drive gear is likely worn and should be replaced.