You should have 1 2 inch of play in the chain.
How to attach a garage door arm to the chain.
Grasp the chain 1 foot from where it connects to the end of the threaded chain anchor.
There is a threaded eye bolt that can be adjusted to get enough slack to attach the chain.
Swivel the arm down and allow it to.
This is where the opener arm attaches the opener to the door.
Pull out the cotter bolt with the pliers.
Pull the chain toward the garage door and hold it in position.
The exact location varies depending on the door.
Attach the bracket that connects the arm the door is opened by one arm that raises it as the carriage travels along the tube.
Attach the bracket that connects the arm to the door then attach the arm itself.
Thread the nut s facing the door clockwise until it meets the bracket then release the chain.