Sounds like a worn drive gear. Gear cost around $30.00 and you can get one on e-bay or a local door dealer. Instructions are included. Only replace the gear, leave the worm gear and bushing etc alone unless they also look worn. It is fairly simple.

Good luck

That sounds pretty simple, will I have to take the box down or can I fix it in place? Is this doable w/out the manual, for I don't have one and I can't seem to find any copies of it online. Also, do you think a 13 yr. opener will still have parts availiable?

Thanks for your help.

You can fix it in place, you will have to remove the opener cover and unplug it. The directions will come with the new part. Like I said before, only worry about replacing the gear. The directions are going to tell you to replace all the bushings and worm gear. Just replace the gear. Yes, the part will be a available for a 13 year old opener. It is the same gear that is in brand new openers. If you run into any problems just post em and we will walk you through it.

How very nice of you to offer. I may be taking you up on it.

Soo... would this be something I can find @ ACE, Home Depot, Lowe's or Sears? Guess I'll need to take out the old gear and take to one of these stores for purchase comparison? (since I don't have any references to part numbers)

You're already holding my hands through this bye the way :)

Don't think it will be available at a local hardware store.

Go to a local door dealer or go on ebay and buy one. You cannot mix it up because there is only one gear for the opener.
FYI:

41A2817 is the gear and worm set
41C4220A is the gear and sprocket set

My Craftsman GDO has the same problem. I removed the cover and the gear teeth are completely worn down in one section. It's very good to know that I can just replace the gear. The worm gear looks still looks OK.

So does it matter which kit of the two listed above is found and ordered, or are both kist needed?

Ok, these are easy to find on ebay. I see the difference now. I'm guessing it would be easier to simply install the pre-assemled gear/sprocket set, than replacing the gear only. What do you guys think?

Oh that is a good question. What do you guys think?

If you look on top of the worn gear or on top of the unit by the sprocket and see ground up metal you should buy the whole gear and sprocket set. If none is found simply replacing the gear is fine as well as replacing the whole assembly. Depends on how much you want to spend. They both are fairly easy to replace.

I went ahead and bought the gear/sprocket assembly. It's Any tips we should know before starting? Also, from what I understand, the grease is fairly important. Is the little amount supplied enough, or is it a good idea to get some more?

The grease that comes with the new part is sufficient enough and yes it is very important. Unplug the opener and remember how you took everything apart.

Best advice I ever recieved was in tech school. "Half of being a mechanic is remembering how to put it all back together once it is apart."

Same thing applies here.

This is my second 1/2 hp chain operated SEARS garage door opener that I will have to replace in 11 years. The big vinyl gear has shredded in both units now after 5-6 years of normal use. I did replace the gear the first time, but it was expensive and did not last very long. When the new gear started to shred soon after it was installed, a SEARS repair person said the shaft was probally bent and it was best to buy a new unit. Until SEARS redesigns thier units without the vinyl gear, I will not be buying a unit from them again.

Larry,

What would you suggest they make the gear out of? Delden operators have metal to metal gears and not only are they extremely noisy, but once they shred and yes they do shred, there is no replacement other than to replace the opener. I would suspect you have a problem with the balance of your door. If the door is too heavy due to wrong springs/not enough spring tension it will cause the gear to wear more rapidly.

I tried to open my garage door, it makes slight sound but nothing moove. This sound only for seconds, the light and the lock works on the pad on the wall. I opened the cover, the gear looks fine. I also remove the board, there was some rust on it on the piece just behind the light. Is my problem with the board or what could be the problem. Any help will be great.

Doorguy,

I had the same problem as sherrys. I ordered the parts but went ahead and replaced the worm gear as the original seemed worn. My problem is that, after putting it all back together, the motor spins in the direction to open the door for about one second before it stops and reverses itself. Seeking to isolate the problem I removed EVERYTHING that attaches to the motor's axle (drive gear and limit switch assembly). For good measure, I also adjusted the up and down force knobs to maximum. With nothing engaging the motor it exhibits the same behavior: axle spins for one second before stopping itself and spinning the opposite direction. Can you tell me why it is doing this? Thanks!

Nevermind--found the problem. I forgot to replace the interrupter cup.

-m

Doorguy:
Any idea what could be my problem with my garage door

hrslaeigh,

Soryy for the delay. Is this just a click noise? If so I would check the trolley and see if it is stuck on something, like a stop bolt in the front or back of the opener. If it is not stuck on something, the first thing I always do is disconnect the door from the opener and see if it runs disconnected from the door. If so, you got a door problem. If not and it exhibits the same problem, you can loosen the chain or belt and take it off the sprocket and hit the button if it still just makes a click noise then the motor is locked up. If it is making some other noise, please specify further.

Doorguy:
Thank you for the response. If the motor is locked up what should I do. And when you say hit the bottom, what bottom?

When I say button, I mean wall button or remote. Something to activate the opener. If the motor is locked up I would just replace the opener. Especially if it is an older model. The motor will probably run you around 100 bucks if you wanted to replace it yourself but, first you gotta see if the motor is indeed locked up. If you go through the diagnostic procedures and find that the motor is not locked up, let me know what is happening, if it is locked up and you want to replace the opener, I would recommend going with a Craftsman or Liftmaster belt or chain drive opener. Stay away from the screw drives.

Doorguy:
I did what you told me, the motor running, the only problem I have now, it does not travel the whole distance eitherway up or down. I tried to adjust it, it seems like it is not taking any adujustments. Any idea what could be next?

Doorguy:
Just to follow up on my previous posting. The chain is off, I am trying to open and close the door without the chain. What happens the trolley moves around like if it is going down, then it comes back. I also, tried it with the chain and it moves the same distance and comes back automatic, I checked the sensor at the door I did not see any problem. Any help from you will be great

hsraleigh,

Again sorry for the delay, I go to school at night and work fulltime, so don't get on here much. So if you take the chain off the motor will work? In taking the chain off it should not open or close the door at all, the chain should have been completely off the sprocket.

Anyway if the motor is working now and the door is only moving short distances and reversing and then stopping is an indication that either the RPM sensor is bad, or that the interuptor cup is off the shaft. Pull the cover off and look and see if the black interuptor cup is on the back of the shaft. BIG BLACK CIRLCLE IF so make sure the little circuit board next to it is plugged in. It has a four prong connector. IF all this checks out good, the RPM sensor is faulty. How old is this opener?

Doorguy
I checked the circut and it is connected. The door is 11 yrs old. Where is the sensor, is it on the big board?
What should I do next.
Thanks

hrsleigh,

Ok, I am lost lets start from scratch. Your initial problem was that the opener would makc some sort of hum or buzz or click noise, but would not move and now that is gone? The opener actually activates now, but only moves short distances. Am I correct so far?

Doorguy:
That is correct, however it moves short distance and automatically comes back.

Ok, the problem is with the RPM Sensor. It is that small ciruit board right by the big black cirlce on the back of the motor shaft. Either the cup is not pressed all the way on the shaft or the senosr itself is bad. You can get the numbers off the the sensor and try and look on ebay for another one or you could opt for a new opener. The sensor is going to be fairly cheap.

I noticed you said you removed the circuit board. Make sure the connection at the board is tight and double check all the wiring. Everyone misses something from time to time including myself and guys with years more experience than me. So just make sure everything looks in place. If so the next thing I would try is an RPM sensor.

Doorguy:
I just want to thank you, my problem was, the cup was not pressed all the way on the shaft

Doorguy,

I had the same problems with drive gear as many others here - replaced it - per your instructions (thank you!) and the door now lifts and closes but I have a new problem:

when I push the button it won't "cycle" correctly,,, meaning it goes all the way down hits and comes back and it doesn't come all the way back up

since I had to cycle this thing without the door attached a few times to position the pins correcty, I fear that the piece that hooks up to the trolley is not in the proper starting position when the door is finished with the "open" cycle.

so when I press button again to "close" it is sitting in "no mans land" about halfway towards the door when it should be almost all the way back by the opener.

since this is fixed to the chain and I can't slide it, is there anything else I can do to fix this problem???

thanks

Vinnie

You need to loosen the chain enough so you can remove it from the sprocket on top of the motor. With the door closed run the motor until that sprocket turns clockwise and stops. Now you can replace the chain and tighten. Don't over tighten. You will probably have to tweak the up and down limits to get it right.

Vinnie,

I would suspect your limits are out of adjustment. Take your chain off the sprocket. Grab one of your remotes and climb on top of a ladder positioned directly behind the opener facing the door. With the chain off the sprocket hit the remote until the sprocket is turning clockwise, let it go until it stops. This will set it on the down limit. By manually moving the trolley (i.e that thing that slides on the rail with the chain connected to it) position the trolley close to the down position. Depending on the way the opener arm hooks to your door it should be around an inch or so from the stop nut on the rail. Put the chain back on the sprocket and tighten everything back up.

This should get you back in the ball park. On the left side of your opener ( if you where standing inside and facing out) you will find two knobs. These are your up and down limits. Hit your remote and see where you are now as far as door travel. You may have to tweak the limit knobs a bit to get you back to where you want to be.

Let me know if you have any problems.

Are you still responding to questions on this topic? The chain runs on mine but does not engage the door.

Please disregard my prior posting - figured it out.

when i push my garage door button all i hear is a click can you help me.please

Is your door stuck in the open position?

I recently replaced the drive gear in my Sears Craftsman GDO with the help from a guru on this site...your instructions made it a whole lot easier than I was anticipating...My problem now is that when I tested it to see if it would work (without the door connected) the carriage came all the way back to the motor and got stuck...I took apart the assembly to relieve the tension from the chain...now the chain seems to be 180 degrees out..when I hit the power button, the door(already shut)goes to the down position and puts fair amount of strain on the chain and track assembly...how do I get back to where it should be?....totally confused...

deacon Hook everything up and then loosen the chain enough that you can lift it off the sprocket. Run the opener until the sprocket turns counterclockwise and stops. Then with the door in the open position replace the chain and tighten. This will get everything back in sync for you.

I made a webpage that includes the printed instructions that come with the gear kit, the part lists, how to reset the door travel etc. Lots of pictures.
http://tinyurl.com/gearfix

Here is a link that might be useful: Sears (Liftmaster) garage door opener gear replacement