Last week, the garage door stopped working. After pressing the button to open the garage door, it made a whirring sound, like a small motor was running, but it was not moving the garage door. Since it was over 15 years old, I assumed I’d had to replace the entire motor.
But after climbing a ladder and looking at the motor, noticed there was a broken cylinder plastic piece that was lying on top of the motor. I took a picture of it with Google lens and it identified it was a garage door sprocket coupler. And it was less than $10 on Amazon.
Replacing the coupler was fairly easy. Just had to remove two bolts on screw drive rail assembly, then I could push back the motor assembly just enough to fit the coupler in. I thought that was easy, less than 5 minutes to fix the garage door.
But when I tried to close the garage door, it closed and then immediately came back up about a foot high and stopped. I thought it might have something to do with the garage door, so I disengage it. It did the same thing. So it had nothing to do with the door. Then I was wondering, when I press the button, how does it know whether to close or open the door? It must somehow think the garage door is open, so it’s trying to close it. But since the door is open only one foot high, it’s trying to close it, but thinks it’s hitting something after just moving it just one foot.
So, I wondered how can I move garage door to the completely open position. With the door engaged, it’s impossible to move it manually. So, I thought the only way is to disengage the door and remove the coupler and manually turn the rail drive screw. Surprisingly, it’s not too hard to turn with your fingers. But, it’ll take forever that way to move the trolley carriage 8 feet towards the motor with my fingers. So used car timing belt to turn the coupler. After 5 minutes, was able to move the carriage to the completely open position.
Tested it with the garage door disengaged, it was then able to completely close and open. And then engaged it and verified it was completely fixed. Glad I was able to get it fixed for under $10. I had tried to search for this situation, but couldn’t find anything. So, if you’re searching for “How to fix garage door if it’s stuck midway”, “How to move garage door manually with the garage door disengaged”, “Garage door stuck third of way up and will not completely close”, “How to manually move a garage door trolley carriage”, then hopefully this will help you.