In the beginning of the video you can hear what this sounds like.
How to replace garage door opener trolley.
Constant rubbing of the rail beam along the side of the trolley will eventually wear away one side of the trolley.
You need to stop the garage door opener when the rack clears the end of the track.
The liftmaster 41b3869 1 garage door opener belt drive trolley sold by north shore commercial door replaces the whole opener and is easy to install.
If the belt breaks or is worn replace it with the manufacturer approved replacement part.
This will disconnect the door from the motor.
The belt connects to the trolley and drives the trolley along the rail to raise and lower the door.
Remove the cotter pin connecting the trolley with a pair of pliers.
Pull the release rope on the trolley and put the door all the way down.
Lower and close the garage door by hand allowing the door arm to pull the carriage to.
Close the door by hand so that the trolley is a the outer end of the rail.
There is a clip holding the pin in the bracket.
Shut the garage door if it s not already closed.
To start pull the old trolley carriage off clamping the chain to the rail.
Pull the emergency release rope to release the trolley from the garage door.
Pull the release cord that connects the garage door to the trolley.
Remove the pin that holds the rail to the bracket on the wall above the door.
Pull down on the release cord for the carriage to disengage the carriage from the drive mechanism in the rail.
The trolley on this garage door the part that travels up and down on the rain was broken.
Simply raise the door with your automatic opener and it will automatically reconnect.
Pull out the clevis pin while supporting the straight arm to disconnect the garage door from the outer trolley.
This diy repair guide explains how to replace the drive belt on a belt driven garage door opener.
Remove the fastener ring from the straight door arm connected to the outer trolley.
Next pull the emergency release toward the door.
This will allow the trolley and rack to run off the end of the track.