Question about liftmaster Chamberlain Garage Door Opener Transmitter 300MC
I hava a Lift master 1/2 hoursepower opner. After changing out the main drive gear the door will close but goes back up upon touching the ground. How do I fix this?
ADJUST THE CLOSE LIMIT SWITCH UNTIL THE DOOR CLOSE SOFTLY, UN CAN DECREASE IT BY TURNING THE FLAT SCREW COUNTERCLOCKWISE.... VERIFY THAT BOTH LEDS OF THE PHOTOCELLS ARE ONE.. OTHERWISE U GONNA HAVE TO ALIGN THEN OR REPLACE IT!
Posted on Mar 09, 2009
Try adjusting the close shut off switch.(limiting switch) It sounds like when the door shuts, it has too much pressure. The sensor picks this up and reverses the door.This is a saftey feature. It just needs adjusting
Posted on Mar 07, 2009
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Posted on Jan 02, 2017
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Oct 17, 2013 | Building Materials
Jun 30, 2017 | liftmaster Home Security
probably did not have the motor shaft pushed all the way back when
you tightened the coupler after replacing the worm gear. Loosen that
coupler up and from the front of the motor (opposite end in which the
coupler is on) push the shaft back as far as it will go. Hold it
there while you tighten the coupler back up and then try it.
If you didn't just change the drive gear you will find the motor shaft is moving towards the rear and knocking the interrupter cup off. Replacing the drive gear with the new coupler and washers will cure this problem.
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