LiftMaster Worn Gear, Sprocket, or Chain/Belt Tension Issues

Garage door opener makes loud grinding or clunking noises during operation.

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Worn drive gear teeth, loose chain slapping rail, misaligned sprocket, dry rail trolley

Safety: Keep clear of moving parts while testing.

Inspect chain/belt: Check tension; chain should have about 1/2 inch of slack at midpoint. Adjust tensioner per manual.
Lubricate rail: Apply a small amount of garage door lubricant to the rail where the trolley slides (for chain-drive models).
Check sprocket: Inspect the top sprocket for wobble or missing teeth.
Replace gear kit: If grinding persists and gear teeth are worn, install a LiftMaster gear and sprocket kit.

Medium 3/5

Gear and Sprocket Assembly

Check Price on Amazon

We may earn a commission from links on this page.