Chain driven garage door opener suddenly has lots of slack


Old 01-18-14, 10:14 AM
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Chain driven garage door opener suddenly has lots of slack

Hello everyone,

I have an old Sears chain driven garage door opener. The other day I decided to accidentally attempt to close the door with a lamp hanging from the rail. The chain jumped the sprocket at the opener itself. I was able to get the chain back on the sprocket without adding slack to the chain but being new to garage door repair, I no longer had the door attached to the trolley. So the opener was working, it just wasn't lifting the garage door properly.I took the chain off again, attached the trolley to the door, and reattached the chain to both sprockets. However, now the chain has a bunch of slack; a BUNCH of slack. I don't know how this could have happened since I didn't adjust the length of the rail or the chain. Does anybody have any experience with this or any idea as to how this could've happened? I should also note that when I operate the opener, the motor spins the shaft that goes up to the sprocket, but the sprockewt itself does not turn. Does the opener require tension to get the sprocket turning?

Thank you so much for your help.
Old 01-18-14, 12:01 PM
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Welcome to the forums.

Without a picture or model number..... it can be a little tough to give you exact help.

It sounds like your opener needs the replacement drive gear kit.

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