CAME garage door opener chain or belt sags noticeably and slaps against the rail during operation

Safety first: Disconnect power before adjusting chain or belt tension.

Steps:

• Locate tensioner: On the CAME rail, find the adjustment bolt/nut for the chain or belt.
• Adjust tension: Tighten gradually until the chain/belt has a small amount of slack (do not over‑tighten). Refer to the CAME manual for recommended deflection.
• Inspect components: Check the trolley and sprockets for wear; replace if teeth are worn or cracked.

Re‑test operation and listen for reduced noise and smooth movement.