Garage door opener seizing - causes?

Those are all good answers and I am glad you discovered the bearing problem. One caution, generally garage doors are "assisted" up by spring tension. This is what allows you to open it with little effort in the absence of a opener. It also makes it possible for openers to be designed with little horsepower. There are two types of springs used. Extension springs are mounted along the track parallel to the ceiling on both sides. A torsion spring is mounted along the wall above the door and parallel to the top of it. If you have extension springs, they may have lost their strength causing more tension "lift" on one side than the other this will get the door in a bind and in a chain reaction parts of the opener may fail. If you have a torsion spring, they can get out of adjustment causing the same chain of events. "CAUTION" most torsion springs require a qualified professional for adjustment (They can kill a person and have). Some of the newer ones can be adjusted by anyone using a drill.

If you have an electric garage door opener that is a screw drive type, try lubricating the full length of the screw with lithium grease. They are often fussy in the winter if not lubricated well.

Check to make sure that all of the fasteners holding the hinges are tight. Sometimes they get loose and cause the door to bind.

Take an old candle and rub it against the door jamb where the door rubs on it when going up and down. This will lubricate that surface. Sometimes with the temperature change the door jambs will shift and cause the door to bind.

If all that fails you may need to adjust the "sensitivity" or "force" settings on the electric opener to a higher setting. Look for dials on the opener's power-head/motor unit.

A couple of things to try...

Once I had a bolt fall out of the "arm" that pulls/pushes the door up and down. That caused it to finish closing about a foot off the ground. You should have a couple bolts holding the arm together - I found the one that fell out on the floor in my garage.

Another time, my garage door would just open and shut at will without me doing anything. It didn't appear that there was anything in front of the sensors, but when I looked more closely, I had lots of spider webs and just dust in front of the sensors. When I cleaned that up really well, the door worked normally again.

do you have an electric powered opener on it... oviously no longer. the subject is once you improve the door, you're pulling to a million ingredient too a lot. this throws it off stability and is inflicting your subject. answer: storage door opener or make confident that's balanced while lifting.

Check the wheels that ride within the track on either side and make sure they spin, and the brackets that hold them to the door aren't loose.