Garage Door Opener Jerks When Raising
Posted by Russell Wright on September 21, 2010
I was noticing that my garage door openers were jerking pretty hard when opening. From a little googling, I found that the garage door “settles” over time and the limit switch settings need some small adjustments. What happens is that the garage door travels too far down and “loads up” with downward pressure, thus causing a big “jerk” when the pressure is released. Apparently this is pretty common and easy to fix.
You should have two adjustments on your garage door opener that adjust the upward and downward travel of the door. Mine have pictures molded into the plastic. I simply backed it off in half- or quarter-turn increments and retested the door. Seems to have fixed my problem.
Well, that really didn’t fix my problem. There seems to be some slop in the screw drive mechanism. Some more googling turned up a screw drive sprocket coupler (Liftmaster 25C20) that seems to be a very common part that wears over time.
I went down to the local garage door opener shop down the street and purchased two of these for $7 each (I have two garage door openers). To replace them, you simply remove the two bolts (7/16”) that connect the track to the motor (located at the top of the garage door opener) and swing the motor drive mechanism back until there is enough clearance to remove the coupler. Drop the new one in to place and position the motor and track assemblies back together and replace the nuts and bolts. This took about 10 minutes per opener. Seriously, it took me longer to get my tools and ladder out and put them back. I’ll let you know if that fixes the problem.
The new sprocket coupler didn’t seem to make any difference. Talking to the garage door person, she asked if the door had recently been painted. In fact it was painted, along with the rest of the house, this past summer. Now THAT’s starting to make some sense. When the garage door sits for some time, it gets “stuck” with the really sticky paint that was used. That’s something I noticed after the house was painted and the garage door seal trim was replaced…the paint on the seal never seemed to get completely dry. It’s always been tacky. I bet this is the root cause. I’m trying some silicon spray on the parts of the door that have paint that make contact.