Q: When is a gear not a gear?
A: When it's missing it's teeth.
The real punch line is that one of my favorite gears, the one in my garage door opener, needs to be replaced (because it's missing all of its teeth).
Signs that the gear is stripped include that the opener sounds like it is working but the chain does not move, and white "confetti" appears below the opener. There was literally a little pile on the ground, as well as plenty more in the cover, which I've removed so you can see it in the picture below:
In doing some research, I found this fascinating comment by Eric on why the gear may be designed to fail first and the larger issue (the garage door assembly probably needs work):
The plastic gearing is actually designed to strip when the GDO is under excessive strain. The “sacrificial” plastic gear saves the more expensive parts (motor, circuit board, sprocket) from being damaged. Garage door openers are not designed to lift doors, they are only remote control devices. The lift is provided by the counter-balance system (springs), which is why you can raise 150-400 lbs of wood or steel up over your head with one hand (a perfectly tuned door can be raised with 2 fingers). If the gear has stripped you probably need work done on the door. Weak springs, blown bearings and low quality/worn-out rollers are typical causes. As for Genie quality, it has diminished greatly in recent years, particularly in regards to their electronics and I certainly hope you didn’t buy the Excelerator model as it tends to damage doors and can in fact be dangerous. Get the door serviced by a qualified technician. Hope this helps, Eric - Garage door professional.Looks like my education in home repair is only beginning...
