Mechanical Disconnect - Chamberlain LiftMaster Professional SW420 Manual

M E C H A N I C A L D I S C O N N E C T
The operator can be disconnected from the gate, so the gate can be manually opened or closed. Disconnect the control arm from the drive hub by
removing the hairpin cotter and then the clevis pin and allowing the manual release pin to drop down through the hub. The arm should now be free
and the gate can be opened and closed normally.
NOTE: If desired, a padlock can be used in place of the clevis pin to hold the manual release pin in place.
Figure 1
Control Arm
Clevis Pin
Drive Hub
Hairpin Cotter
Release Pin
13