The gear and sprocket assembly is inside the cover of the garage door opener motor.
Garage door chain gear broke.
Garage door openers.
Press down on the chain with your finger.
The gear will cost about 50 00 with shipping and then the cost of having someone install it.
The most common cause of a chain being loose and appearing broken is a broken gear and sprocket.
Remove the outer nut and lock washer from the trolley threaded shaft and pull the threaded shaft out of the trolley.
Slide the outer trolley away from the inner trolley.
If your chain is badly corroded you may need to remove the chain from the carriage assembly and soak it in lubricant for a few hours.
I hope this will help.
Grasp the chain 1 foot from where it connects to the end of the threaded chain anchor.
Move the ladder to the outer end of the chain arm near the garage door.
Loosen the bolts on the chain pulley that s attached at the top of the arm and slide the pulley one inch toward the motor.
A broken garage door chain will immediately impact your garage door s operation and render its automatic motorized capability effectively useless.
How to lubricate a liftmaster chain driven garage door opener.
To do this put some lubricant on a piece of rag this use the rag to wipe the chain.
Periodic maintenance of a liftmaster chain driven garage door opener includes lubricating the chain and greasing the chain rail.
Lay the chain on the garage floor while you complete the repair.
If the chain on your garage door is rusty you need to apply lubricant into it to loosen the corrosion.
A new garage door open start around 130 00 plus installation.
Thread the nut s facing the door clockwise until it meets the bracket then release the chain.
Pull the chain toward the garage door and hold it in position.
It will usually run about 200 00 total.