How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Brian Your Own Question
Brian, Architect
Category: Home Improvement
Satisfied Customers: 3123
Experience:  Licensed Architect- 17 years, L.E.E.D. AP
Type Your Home Improvement Question Here...
Brian is online now
A new question is answered every 9 seconds

I have a Craftsman garage Door Opener (model 139.53637SRT)...

This answer was rated:

I have a Craftsman garage Door Opener (model 139.53637SRT)... 1/2 HP.. 120V... 5.0 AMP... 60 Hz...

Was working fine until about 3 hours ago when it stopped working... tried to open it and the door came up about 6 inches then stopped... when I tried to close it to try to reopen, the motor hummed for about 3 seconds, stopped, then hummed another few seconds, but the door did not move... I tried a couple more times with the same result... I checked the springs, pulleys, safety cable, rollers, trolley, etc.... everything is free and clear... I disconnected the door from the trolloey and it works fine manually... I tried the opener again to see if it would work without the door (just the chain & trolley)... still hum-stop-hum ... then I disconnected the chain altogether to see if the sprocket on the unit would turn... it did not turn and the unit again just hummed-stopped-hummed again... as a last resort, I tried adjusting both the force and travel distance up and down but that did nothing..

Any thoughts?

Hi, my name is XXXXX XXXXX I will be helping you today.

Thanks for the thorough explanation of your symptoms. With everything you have done the humming is most likely being caused by stripped or binding gears inside the motor unit or you need a new start capacitor.

I would unplug the unit, take the cover off and inspect inside. See if the gears are in good shape and hopefully not plastic shavings everywhere. Inspect the capacitor; it is a cylinder shape and if it is bad, you will often see the sides bulging or it could be leaking fluid.

If you are satisfied with this answer please leave me a positive rating at your convenience.

Customer: replied 4 years ago.

There are plastic shavings and the large gear wheel is worn some... but it still seems to have sufficient teeth to mesh with the main turning gear...

Do you think I could find replacement gears for this unit (manufacture date of 1995)???.. and would replacing gears (if available) be cheaper than a new unit???..



The capacitor looks fine... clean... no bulge... nothing leaking...

Well it sounds like the gears are the problem. You can purchase a new one online at any garage door parts website. Just have your make and model number of the unit. It will be cheaper to buy new gears than a new unit.
Brian and other Home Improvement Specialists are ready to help you