Question about Sears Craftsman LiftMaster Chamberlain Garage Door Opener Wireless Keypad Model 976LM Security+

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Garage door won't go down because of interference

The trolley? (the part that is connected to the chain and slides over the rail) that pushes the door down seems to be jolted at a connection joint of the rail. At first it made a banging sound but closed. Now it hits at the same spot and the door goes back up. I disconnected the door to fiddle with the trolley and it worked one time. Then it started banging again.
Can the trolley be replaced?
Any help would be appreciated.

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IF YOU ARE TALKING ABOUT THE JOINTS IN THE RAIL THE TROLLEY TRAVELS ON THEY USSUALLY ONLY GET OUT OF ALIGNMENT WHEN THE BOLTS THAT HOLD THE SECTIONS TOGETHER ARE LOOSE.

Posted on May 28, 2010

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It sure sounds like you have a broken door spring. While you are at it remove the cover and take a good look at the drive gear. It is white nylon and is just in front of the motor. Might be stripped and unable to take the weight of the door.

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1 Answer

Garage dr won't close because trolley interferes with rail joint


Run the unit with the door unhooked.
Work the door manually.
If the door works smoothly and easily up and down and the opener works normally when not connected to the door you probably have a bad gear kit.
Unplug the unit - take of the cover – if you find white shavings inside – these confirm the diagnosis. .

Get the gear AND sprocket kit.

It’s a good DIY project but you MUST VERY CAREFULLY Follow the instructions step by step.

HOPE THIS HELPS


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