When the springs can t handle the weight it puts the burden on the opener which then weighs down the trolley carriage.
How to replace a trolley on a garage door opener.
Swivel the arm down so that it is even with the side of the door.
Slide the new rack and the trolley on the end of the rail until the teeth on the rack engage the screw drive.
This will disconnect the door from the motor.
I have a craftsman 1 2 hp garage door opener which recently had a part break on me.
Run the garage door opener in the down direction until the trolley and rack come off the end of the rail.
To start pull the old trolley carriage off clamping the chain to the rail.
In the beginning of the video you can hear what this sounds like.
Once the wear and tear is too bad the garage door won t open at all or will open but not easily.
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.
Lower and close the garage door by hand allowing the door arm to pull the carriage to.
Lots of other garage door openers starting with 189 but not my exact model.
I think the part that broke is a sub component of the trolley.
Constant rubbing of the rail beam along the side of the trolley will eventually wear away one side of the trolley.
Pull the release cord that connects the garage door to the trolley.
Close the door by hand so that the trolley is a the outer end of the rail.
Remove the cotter pin connecting the trolley with a pair of pliers.
Pull down on the release cord for the carriage to disengage the carriage from the drive mechanism in the rail.
Run the garage door opener in the up position until it is well onto the rail or until it stops at the up position.
The model on the unit is 139 18060 which i can t seem to locate on searspartsdirect website strangely enough.
Simply raise the door with your automatic opener and it will automatically reconnect.
Next pull the emergency release toward the door.