This gear kit on amazon.
How to replace nylon gear on old garage door opener.
This was a craftsman model 139 53976srt.
Once your old garage door starts making weird sounds or fails altogether set aside some time on the weekend to replace it.
How to replace old garage door openers.
Step by step garage door opener gear fix.
So if you suddenly find that the motor on your garage door opener sounds like it s running but the door is not moving checking for worn gears is the first thing you should do.
Shredded plastic gears are a common problem with chain driven garage door openers.
If yours is a belt drive you need a kit like this https amzn to 2zqns.
Fortunately the repair is neither difficult nor expensive and it should only take an hour of your time.
This is a video on how to change the gear sprockets in a craftsman garage door opener.