Question about liftmaster Chamberlain Garage Door Opener Transmitter 300MC

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Liftmaster garage rack won't return/open. It gets stuck about 1ft from the closed position. I thought the rack was stripped but it seems fine. The motor is really loud. When I press the button again the rack goes to the end & just keeps trying to keep going (away from the motor). There were no issues leading up to this problem.

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  • 3,382 Answers

It sounds like something needs lubrication badly or the track is not aligned properly with the door and it is binding. It is also possible the limit settings are way off. Sorry I cannot offer more help.

Posted on Apr 29, 2014


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Posted on Jan 02, 2017

  • 118 Answers

SOURCE: My Liftmaster garage door opener will not close

You have a problem with the safety eyes. Make sure both eyes have a lit Led light, if not realign sensors

Posted on May 15, 2009

  • 25 Answers

SOURCE: Liftmaster Remote garage door openers work intermittently.

check to see if your ant. is up inside of the cover it's a little black wire that hangs outside of the operator shiould be about 6 inch.

Posted on Jun 07, 2009

  • 25 Answers

SOURCE: Chamberlain Liftmaster 1246R won't open/close

if youcan hear the motor turning when you hit the remote or wall button the plastic gear in the oprator has been ripped and if you take the cover off you will see all of the whote plastic dust that has come from the gear being shreded. You can replace this gear. you do not have to buy a new operator. it is very easy to replace this gear. I can't tell you were to buy one because I buy all my stuff from a dealer.

Posted on Jun 11, 2009

  • 25 Answers

SOURCE: Garage door will not close from remote or car.

wI have never heard of this problem. you have to hold the button on your wall in to close the door. no way this is not right something wrong with your board insid the opener. get help from a pro. I would love to see this been doing this for 20 years never heard of this.

Posted on Jun 20, 2009

  • 384 Answers

SOURCE: door opened and will not close or open now

Drive should have a feature to disconnect from door to allow for manual closing.

Posted on Jul 15, 2009

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I have a 3/4 horsepower liftmaster garage door opener, both the remote and the wall button won't close the garage door but both will open the garage door. however, the garage door will close if I hold...

If when closing the door it reverses to the open position and the main light flashes 10 times it is a door sensor problem. Make sure the small light on each sensor is on and not flickering ever so slightly. (check closely) Tweak them a little even though they may seem to be okay. Check for 5vdc between terminals 2 and 3 on the rear of the motor unit. If there is no voltage or if it is greater than 6vdc the logic board is bad.

Sep 26, 2011 | Sears Craftsman LiftMaster Chamberlain...

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My garage door wont open or close the moter makes a funny noise like its stuck i checked the sides checked the strap everything seems fine

Take the cover off the motor unit and check the drive gear. It is white nylon and will be very obvious if it is stripped which it most likely is. The part number is 41A2817 and is available at any good door opener service company or Sears. It comes with instructions.

Dec 28, 2010 | Sears Craftsman LiftMaster Chamberlain...

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Liftmaster pro 1/2 hp wont shut in one button press

You have a door sensor problem. Either your main light bulb is burned out or you don't have one in your opener. The clicking sound you hear is the relay for the light. Both of the door sensors should have a small light that is lit. Tweak them until they are.

Jun 28, 2009 | Sears Craftsman LiftMaster Chamberlain...

1 Answer

Craftsman Liftmaster

Check your door springs. One of them is most likely broken and is what caused your drive gear to strip in the beginning.

Jun 18, 2009 | Sears Craftsman LiftMaster Chamberlain...

1 Answer

Garage door will not open

Remove the cover and check the drive gear. It is white nylon and is just in front of the motor. It is most likely stripped.

May 17, 2009 | liftmaster Chamberlain Garage Door Opener...

1 Answer

How do you replace rack on liftmaster? Mine is stripped

why stripped again in only one year. is door balanced. lift half way and let go (Opener disconnected) and does door stay there? If it slams down, check springs.

Feb 07, 2009 | Sears Craftsman LiftMaster Chamberlain...

1 Answer

Stripped gear

Try opening and closing your door by hand with the motor detached (detach it by pulling on the rope) It should open and close easily without a lot of effort. If it catches or is too heavy (possible broken spring) it will strip the gear. The door has to be working properly before you can attach an opener to it. If you lift your door up about waist high and let go of it . It should not go up or down but should stay in that position, This tells you that the springs are correctly adjusted

Feb 04, 2009 | Sears Craftsman LiftMaster Chamberlain...

1 Answer

Liftmaster rack keeps stripping

what do you mean by rack. do you mean fears. do you have right sprigs on door, is door balanced. lift half way and let go (Disconnected by arm). It should stay put or go slowly up or down. If not, springs are bad, I put a 1/4 hp on 18' wood door. lasted 27 years so far. H/p not the problem.

Mar 15, 2008 | Sears Craftsman LiftMaster Chamberlain...

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