Guardian opener rail flexes excessively or moves at the header when door starts moving.

Safety first: Disconnect power. Use proper ladders and avoid working under an unsupported door.

• Check header bracket: Tighten lag screws securing the Guardian header bracket to the wall framing. Replace with longer lags if they are stripped.
• Inspect hanging brackets: Ensure the opener is hung from solid ceiling joists with angle iron or manufacturer-approved brackets, not just drywall.
• Seat rail fully: Confirm the rail is fully inserted and locked into the opener head.
• Add bracing: If the rail still flexes, add additional angle-iron bracing to stiffen the installation.