garage door problems

[that-guy]

bought a house with a detached 24x24, 2 car garage, for which neither door motor worked. on the right side, is an older craftsman that has a stripped plastic gear (very common problem on these) so I bought a kit to replace the gears and bushings, so now it turns, however no matter how much I adjust the travel and the sensors, it doesn't go down but maybe a foot, and comes right back up, even if I disengage the door from the chain, it still does it

on the other side, I get power, but then nothing happens...

anybody around the King George VA area that would care to possibly take a look, and/or give some insight on what I should do?

 

[LB-1911]

Not an uncommon occurrence after a gear replacement - Give this a read -

If you have recently replaced your garage door opener's gears, the shaft bearing kit may be interfering with a part of your RPM sensor assembly called the interrupter cup. Make sure that the wire harness is plugged back into the RPM sensor and the interrupter cup is installed and seated all the way on the motor shaft, so that the edge of the cup rotates through the RPM sensor. The RPM sensor is a small 1 inch x 1 inch electronic circuit board with a 2 pronged black sensor. If the cup is not pushed on to the end of the shaft, it can cause the symptoms described.


If the motor shaft moves back and forth through the motor more than 1/16thof an inch during operation, it could lead to the door traveling only a short distance before reversing. Ensure the motor shaft is tightened enough so that there is not too much "endplay" in the shaft. Endplay is caused by a loose or improperly installed shaft bearing kit. Loosen the set screws on the shaft collar, press firmly on the collar towards the motor, then while applying pressure to the retaining ring tighten the set screws.


http://liftmaster.custhelp.com/app/...r-only-travels-a-little-way-and-then-reverses

 

[that-guy]

thank you for that LB-1911...I know I plugged everything back up properly, but I will look into all of that tonight

 

[Jagmandave]

On some openers here is a torque adjustment too, you tighten it down till it works then back it off till it does what it's doing now, then tighten back down just enough to work again, plus a smidge.

 

[that-guy]

On some openers here is a torque adjustment too, you tighten it down till it works then back it off till it does what it's doing now, then tighten back down just enough to work again, plus a smidge.

where would said adjuster be located? I see the "up force" and "down force" screws, and the "travel distance" screws

 

[Cougar]

where would said adjuster be located? I see the "up force" and "down force" screws, and the "travel distance" screws

Be careful with adjusting that. Thought mine needed an adjustment but it was the door that was the problem. Adjusted it until it took the gears out.

 

[Trey T]

I would check to see if hte door is still balanced or not and see if the drum is rubbing against the bracket or not.

I had same problem and I had to move the drum in about 1/8" to clear the rubbing caused by the thimble-end of the cable.

 

[kramarj]

If the light bulb is flashing when it reverses, then the safety eyes are the problem. If not, then it is most likely a problem with the down force setting, which most of the time can be found on the back side of the opener, there will be two adjusters that kind of look like screws. One screw is for the down force, the other is for the up force. We normally adjust them so that they point straight down, so about half of the allowable force. If you have to adjust them so that it takes more force than that, your door works too hard and it has to be fixed first.

As long as you have some mechanical ability, I highly doubt you messed anything up by installing a new gear in it, it is pretty straight forward. Most likely it is either the safety eyes or the down pressure.

There is also the possibility there is an issue with the circuit board or rpm board, but they really aren't that common of a problem in those openers and the symptoms aren't really there for it. It can't be ruled out though.

 

[Jagmandave]

Like Trey T says, check the free operation of the door first, make sure it's not binding or dragging and the springs are set strong enough to support the weight of the door.

 

[that-guy]

I have adjusted all of the screws to no avail in many different configurations. because of this issue, I pull the cord to unlatch the door from the slide so I can pull it up and down manually, for which I feel no resistance or reason to think that the door is at fault. even when the slide is not bearing the weight of the door, the action is the same, so I know it is on the motor end, and not on the door

 

[Trey T]

^Turn the force down and try this: if you assist pushing the door down while opener operates, does it help?

If so, then it's your door.

 

[upndown]

I'm assuming both sensors are lit?
Did you replace the worm gear as well?
If so it could possibly be something as simple as shimming as well, make sure the cog wheel(hub) is seated properly. This can all cause a faulty reading by the RPM sensor. It doesn't take much to damage the sensor board! As mentioned above, doesn't happen often, but I have replaced a few.

 

[DeliveryGuy]

The rpm sensor is not keyed, and can be installed one tooth too low on the four pin connector.

 

[BillK]

Just wanted to add that you can download all of the Craftsman instruction manuals from the Sears web site. That would be the first thing I would do. That way you will know what all of the adjustments are and how to do them.

 

[that-guy]

Just wanted to add that you can download all of the Craftsman instruction manuals from the Sears web site. That would be the first thing I would do. That way you will know what all of the adjustments are and how to do them.

Hey Bill, I have used your machine shop for many of my motors over the years...I will research and find my specific manual and see what I can find from it