Great video. Just want to add that if folks are putting the screws in manually, threading them in to the new part BEFORE installing (then removing) it will help a lot to have them screw in easier. Also, removing that bottom gear allows you to move the little 'trolley' if you need, to get it into the up or down position.
Just ordered my new sprocket assembly from Amazon. Thanks dude! You just saved me over a hundred bucks!!! I will film how my job goes and my wife will be so proud of me!!! ...YO!
Awesome write-up and tutorial......I used to to do my install of new sprocket that U got off Amazon as well......First time ever messing with a garage door opener and it was a breeze Thanks to the video....
Rico - I just completed mine and noticed you did the exact same thing I did. When aligning the hole ensure the chain cover holes are @ 6:00 if you want to reuse the cover. I went without after I realized the holes were off; just like your video. No biggie Thanks for the inspiration.
Good video. thank you. I also had instructions with my new sprocket and shaft to remove the motor to replace the worm gear. This wasn't easy as I broke a bush trying to pull it off the motor shaft. Luckily I managed to remove it with the aid of an extra pair of hands and a bench vice but think if I knew how difficult it was I would have left the old worm gear on.
Great video since it addressed the same issue as mine: replacement of the drive gear. Other videos I saw want you to disconnect this board and that sensor, etc. Same with written instructions that you can find online, or the ones that they send you with the parts, but you don't need to remove all that. I think they're also replacing the worm gear which was not my issue. Or by removing all that other stuff, you get easy access to that third screw which is a real bear to access if you don't remove other stuff. My issue was that the sprocket that pulls the chain around just sheared off (due to overly tight chain?) so I had to replace it and the drive gears below which all come attached together when you order it from the internet. They also send you grease. And they send the worm gear even if you don't need it. This is what I ordered from Amazon for my Craftsman Liftmaster opener 1/2 Horsepower: LIFTMASTER Garage Door Openers 41C4220A Gear and Sprocket Assembly Sold by: 365GarageDoorParts Good luck. Do make sure that the door is closed and the inner carriage is in the down position when you put the chain back on.
You should go back inside the head unit, and lube those nylon gears and steel sprocket shaft with some lithium grease. That's the reason people have to replace their openers all the time. The doors need to be readjusted over time also. If the springs are adjusted properly, the open simple has to MOVE the door, not actually lift it. That's why there are springs to assist the opener. I've had my first Chamberlain/Craftsman/Liftmaster (all made the same) for over 30 years.
Thanks for that. I wish you would show how you took off the cover plate. Now I have a 5/16” socket head stuck inside the tunnel on the bottom right side while trying to get the bolt out.I tried squeezing a long skinny slotted screwdriver in between the stuck socket head but it’s not turning out. Lefty Lucy. Looks like there are more like that on the top. Can’t get any of them to break free. Wish me luck and if you are about to do this easy project, don’t use a 5/16” socket to remove the cover plate.
Great Video, Thanks! Do you think you could put the screws from the top instead of from the bottom after replacing the part? Waiting on exact parts to come in mail to fix my 30 y.o. opener.
Has anyone done this, swapped both gears, and then had a loud rattle coming from the gears? When the door is raising, these gears rattle like crazy. I tightened all the mounting screws and confirmed everything is in the correct order.
I have the same model but could only get the plastic gear but not the whole shaft assembly. It also came with a roll pin. I replaced this gear a few years ago but can't remember how I did it. How do you get the nylon gear off and back on the shaft?
It's really funny that this just happened to my garage, and literally the first video that I look at his the same exact unit that I have. LOL thanks a lot. do you have a direct link to the exact gear that I'll need to purchase?
I am having the same issue, just to confirm that, does the shaft (drive gear rotate manually)? what I mean to ask is, how to confirm that drive gear is not working?
It's typically the bearing at the top of the unit just below the sprocket that the chain wraps around which fails. You can see in the video right at the 25 second mark that his bearing has failed because the sprocket is leaning forward slightly and there's some junk from the bearing stuck in there under the sprocket too. The opener probably would still work if the chain was hooked up but would have problems because of the extra slack from the sprocket leaning forward slightly.
Hi Adam in my b&d control a door the vertical shaft has dropped and disengaged from the top sprocket. Is there a key or a pin to stop this from happening and what is the easiest fix ? regards John
Hi Jack. From watching many of these videos, check the metal sprocket gear that drives the chain. Also be sure to review the up / down door settings for your door. Next is the door weight / force settings of your unit. Make a note of the current setting and then reset them to the minimum for each. Then replace the gears, lubricate with the supplied grease. Configure the door settings to suit but it is important to not have too high force settings. Otherwise you are telling the unit to apply that much more force before stopping the motor. Believe this is leading to the premature nylon gear wearing. The replacement kits are available with and without the metal sprocket. I think it is more practical to purchase the one with the metal sprocket assembly. Personally sourced it from Amazon. Good luck!
Did this and now my door only opens 6 inches, stops and goes back the other way 6 inches, then the yellow light flashes 5 times. With or without the garage door released. Any suggestions?
Thank you!! Mine was doing the same thing and I was dragging my chain/trolley into different positions trying to figure out what the hell was going on. Forgot I removed the plastic cover you mentioned and didn't even think about it as it looks like it doesn't really have a function...but apparently it does.
Can someone help me out here, I replaced the sprocket and the chain is going in reverse. So instead of pulling the garage door open it’s closing even thought the garage door is closed
