Garage door will not work

Hello,

The problem is not the chain, it is the plastic gear in the unit of the liftmaster Garage Door 1/2 Hp.The plastic gear is not engaging, although it sounds like it is working.

You will have to replace it with a new one, then the liftmaster Garage Door 1/2 Hp will be able to open up once again.

Once you open and remove the old gear, Be sure to thread the screws in all the parts before you install them. Pre-threading them once would really help. Secondly, label the wires on the back of the opener before lowering it to the ladder, so you can put them back in their proper place.

Hope this was helpful.
Goodluck
Elect_Comp

The shaft on these garage door motors are not direct drive systems. You'll have to open up the box to see what the actual problem is. I have had stuff like this happen where a gear just slipped out of place.

http://www.aaadooropeners.com/?gclid=CLH3wt628p8CFVZS2goduwSLYQ

Here is a link for a parts supplier. I don't know your model but it looks like most of the Liftmaster worm screw gears and drive gears are plastic so it's possible that one of them has cracked.

Use that small tube of grease in the kit and smother the gear teeth with it. Use it all. Also disconnect the opener from the door and lift the door by hand. It could be the springs are either broken or so heavy the opener can't survive lifting it.

Make sure you put the black cup back on the end of the motor shaft and that it is pressed all the way on. Make sure the RPM sensor is plugged in. If neither of these are the issue, then you probably did not have the motor shaft pushed all the way back when you tightened the coupler after replacing the worm gear. Loosen that coupler up and from the front of the motor (opposite end in which the coupler is on) push the shaft back as far as it will go. Hold it there while you tighten the coupler back up and then try it.

Make sure you put the black cup back on the end of the motor shaft and that it is pressed all the way on. Make sure the RPM sensor is plugged in. If neither of these are the issue, then you probably did not have the motor shaft pushed all the way back when you tightened the coupler after replacing the worm gear. Loosen that coupler up and from the front of the motor (opposite end in which the coupler is on) push the shaft back as far as it will go. Hold it there while you tighten the coupler back up and then try it.

you need to replace gear when the door is fully closed. then do your tweaking.

as long as the door is less than ten years old, sears will stock the part you need. you can contact them through this link.

http://www.searspartsdirect.com/partsdirect/index.action?psid=58709328&sid=PSx20071217x00001a

havent heard any of yu say you adjusted the down force.

It sounds like you did a really good job! My Craftsman 1/2 hp gar. dr. opener has a red reset button on it on the l/h side as you are looking at the light/motor from the garage door opening. You have to take the light cover off to be able to see it. My reset button is on the same side as the ground wire. You might check the ground wire while you're there. I really hope that this fixes it for you (and me). I'm quite sure it will as you know your way around the garage door opener already. Good Luck and Let me Know (Please) if it fixed it or not. If I think of anything else, I'll let you know. Have a Good Day!

I have the same problem. I just removed the cover and discovered a nylon gear had been worn out. I found lots of shavings inside the cover. The nylon gear is beneath the exterior chain gear. I am looking for information on how to replace it, if I can find the part. If you decide to look at yours, unplug the power and remove the sheet metal screws securing the bottom portion of the cener cover to the front and back covers. Then just remove the upper screws from the center cover. Good luck.