Still another garage door question

[Bob-tx]

On our house garage, we have a double light weight steel door and a Craftsman door opener.

Every time the temperature falls much below about 40 degrees, we have a problem that only occurs when closing the door.

The door goes part way down and reverses. It has done this for years, and I can live with it because it seldom gets below 40 degrees here, but it would be nice to fix it, or at least know what causes it.

I have lubricated the roller bushings, the door panel hinges, the horizontal spring across the top, and the drive chain, using a can of spray lube that says it is designed for garage doors (I know, sucker). The door goes up and down easily by hand and is quiet in operation.

Any thoughts?

Bob-tx

[Eric in North TX]

Check the alignment light on your safety electric eyes at the bottom of the track next time it happens. Check them when it isn't happening for a baseline. Something could move when the metal cools.

[Twayne]

My first guess would be the setting for how much pressure before it reverses direction; can't think of what it's called in the manuals. If it's too sensitive, the door can reverse itself when it shouldn't. Perhaps the cold changes something somewhere that gives the door just a little more friction, causing it to reverse on you.

Sometimes, when testing a door to see if/how it's sticking, you have to push it down from the same place the opener acts on it; where it attaches to the opener in other words. Careful though, don't just climb up on a ladder and give the door a push; it can be dangerous and if the door sticks & unsticks, it can unbalance you. I ran a rope thru the place where the opener attaches to the door and looped it over a handle I added to the wall over the door. It worked and I found where it was sticking. From that I discovered a slight misalignment between the horizontal track and the curved part, and a roller bracket was catching on it. Adjusted the track a tad, and voila! But you could move the door up & down all day by its bottom and it'd never catch there. Someone here mentioned to try the method I described and it worked pretty well. Like I said, beware just doing it from a ladder; put somethign under you in case you fall & have someone the help hold the ladder, at least.

HTH,

Twayne

[Tomes]

"Twayne" ...

It is often called downward force adjustment and it is a screwdriver adjustment on the side of the unit. You want more downward force so it gets past what it considers to be a binding point.

I had this problem on my old doors and I made this adjustment and solved the problem. Tomes

[Malcolm Hoar]

Metal and cold temps -- think thermal expansion/contraction.

Something has contracted sufficiently that one or more of the safety sensors is tripping and setting the opener into reverse.

Have you checked the door manually when the temperature is low? Try it early in the morning before sunrise on a cold morning -- chances are high you'll find something binding or catching.

If that fails, you can probably work around the problem by adjusting the pressure/other sensor sensitivity by a VERY SMALL AMOUNT. Obviously, it would be foolish to adjust those controls by a large amount thereby disabling the very worthwhile safety features that can prevent serious damage and/or injury.

[jim]

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If you put to much down pressure on it , it will it the ground and bounce up.

[AZ Nomad]

There should be an adjustment for the maximum current draw before it reverses. Try turning it up a bit. See if sears.com has online manuals if you've lost yours.

[Bob-tx]

Thanks for all the replys. I have adjusted the down-force pot, just a little bit at a time, until it is full max, but it didn't change anything.

No, it isn't the alignment of the safety sensors. I checked this several times over the years.

I think that the idea to try the door motion by manually pushing from the top (the way the opener does) is a good idea, and a logical next step.

Thanks, Bob-tx

[AZ Nomad]

You had said that "The door goes up and down easily by hand'.

Maybe something in the drive system is binding? What kind of mechanism is it? A chain drive? Perhaps there's a bad link that binds when it goes "around the bend"? A bent spot in the carriage that only causes a bind when the drive is engaged?

[Bob-tx]

I can't see where this would cause a problem only in cold weather. Also, about three years ago, I replaced the unit because of another problem with it, and they both do the same thing. Bob-tx