Chamberlain 41C4220A LiftMaster Gear & Sprocket Assembly Kit

El kit de engranes de repuesto lo utilice en un motor de garaje craftsman.Si fue compatible y embono perfectamente.Lo único malo y es por eso las 3 estrellas es que viene empacado en una bolsa de plástico y así lo manda Amazon... por ser frágil en los dientes de los engranes creo que camberlain debería ser más profesional y mejorar el empaque.

fit up was good. everything functions well and the lift is quite a bit smoother than it was with the old worn out parts. Instructions were a little bit cluttered to read, so go slowly and read carefully(check marks or highlight what you have completed as you go).

The product is exactly as needed, at a good price.

Everything worked well, perfect match

Easy to install (with the instructions provided) all parts included and, in my case arrived a day earlier than expected.

I read a couple of the reviews on this page, I have two garage door openers, Raynor Pilots, that the bushing under the sprocket had worn completely away so you could no longer tension the chain. These are 6years old but I have heavy wood over-laid doors. The worm gear and main gear were both fine but the bushing was shot so this kit was perfect even though I had some parts left over.I did this with the garage door fully open, the instructions say to have it closed for safety reasons. I used a 2x4 to prop the door in the open position at the top of the normal travel of the garage door, I did this for two reasons 1) the open door gives you a great place to put parts and tools while you are working on the opener (toss a piece of cardboard on the door some of the parts are greasy!) and 2) the chain will not fall to the floor. Make sure you prop it up with something solid as the door will move downward when you remove the chain and unplug the opener.Remove the chain from the unit, 1/2" open end wrench (13mm) and let the end hang over the opener. I only needed to remove the opener cover, 6 screws, and then it was easy to remove the 3 screws holding this assembly in place. I used a 8 mm socket with a 12" extension on two of them and had to use an open end wrench on the other one. Once these are removed you remove the retaining clip on the travel gear and it pulls off and you can remove the entire unit through the top. The holes for the sheet metal screws are not threaded so either run a screw through them before you install it or tap the holes with a coarse tap. I applied the supplied grease on the gear before installation, slid the unit back in through the top and tightened up the screws. Once you place the limit gear back on the bottom and installed the retaining clips you are nearly done. before I put the chain back on I ran the opener through a full cycle to make sure everything worked well, just make sure you do a complete down and then up cycle so the unit stops at the top. Put the chain on and tighten so that the chain is 1/2" off the rail and install the cover.Run the door through the cycles, check the top and bottom limits and adjust as needed with the limit screws. Double check the closing force and you are done. Both doors took me an hour and saved me a couple hundred bucks!

I benefited greatly from comments others made about this product and how to install it, and I thought I'd add mine for any who are looking at getting this. My 11-year-old Liftmaster chain drive garage door opener stopped working and had the same worn out sprocket that so many have described, with the white snow shavings, etc. I too feared I'd have to spend $100s getting it fixed, then I found this great product on Amazon. I installed it last night, the whole process, including finding tools and adjusting the chain and door afterward, took me about 2.5 hours, but the actual removal and installation of the part took only about an hour. Garage door works great now, and is quieter than before.For the installation, I did what the reviewer before me did, which means I didn't remove all of the stuff the instructions said to remove. Here's a fairly detailed step-by-step of what I did -- my inner and outer "trolleys" (the things that slide the door along the rail and that have the red release handle) were already connected in a good position with the door closed, so I didn't have to adjust anything there: (1) unplug the unit and loosen chain following directions -- I suggest loosening as much as you can -- I didn't at first and had to loosen more to get chain off, which added time to the overall project; (2) remove chain from top of opener unit and attach it to rail so it doesn't fall -- I did this with a plastic tie thing; (3) remove three-sided housing from opener (total of 8 screws hold it in place); (4) unscrew back side of housing (2 screws at top corners), the one that has the circuit board, and let it just hang there (I didn't remove the front side of the housing); (5) remove the white plastic clip and little gear/sprocket from the bottom of the old spindle -- the plastic clip came off by just pulling the front prongs apart a little and pushing it out and the little gear piece just comes down and off; (6) drop the door travel sensor/adjuster thing by squeezing the top of the plastic bracket that holds it where the bracket hooks into the metal plate above it, and let it hang (not sure this needed to be done, but I did it); (7) remove the 3 screws holding the spindle assembly in place at the top of the unit -- this was the "toughest" part and, in part I think because I didn't remove the motor or other parts per the instructions, it was a little tricky getting to the three screws, especially the one nearest the circuit board and a little obstructed by a small bundle of wires, but with patience and care and the right tools it can be done -- I used a small ratchet wrench with an extension (extension was needed for two of the screws) I think the socket I used was 5/16"; (8) remove the old spindle through the top; (9) the screw holes in the new part are not threaded, as others noted, so I threaded them by putting a screw starter (an awl-like device that I think is designed for wood) into the screw holes in the new part and turning it as much as I could and then driving the screws part way into the holes and then taking them out -- all of this with the new part on the floor of the garage; (10)clean the mound of white plastic shavings off as best I could from the metal "shelf" above which the white plastic "screw" is located (like others, I didn't need to replace the plastic screw); (11) remove the white plastic clip and small gear from the bottom of the new part (not sure this was necessary, but I did it); (12) drop the new part in place from the top and screw it in place, being careful to align the square holes for the plastic sprocket cap on top of the unit, front and back, if you want to be able to use that cap -- screwing the new part in place in the tight space with the motor in place was again a bit tough, but doable with patience and care; (13) replace the small plastic clip and gear at the bottom of the spindle; (14) snap the door travel sensor/adjuster bracket back into place in the metal shelf above it; (15) use the supplied lubricant and an old toothbrush to lube up the new sprocket, the old screw and the gear at the bottom of the spindle; (16) plug the unit back in and run it briefly without chain attached to make sure it works; (17) reattach chain and run the unit to see if adjustments need to be made on the door's "travel" -- mine needed a lot of adjustment because it was going down too far on the close and not coming up far enough on the open -- I also put some oil on the chain, the sprockets on either end of the chain and on the rail before running the unit with the chain attached; (18) put the sides back on the unit.Sounds like a lot, but it's very doable with patience and care, especially in removing the screws to get the old part out, starting threads for the screws in the new part (with the part on the floor), and screwing the new part back in. My socket wrench slipped a couple of times while removing the old part and putting in the new part, but, fortunately, I didn't hit or break any vital part. The only tools I used were a flat head screwdriver, a socket wrench with extension and one socket (5/16", I think), a screwstarter awl-like tool to thread the screw holes in the new part, an adjustable wrench to loosen the chain tension, an old toothbrush to spread the lubricant, a plastic tie thing to secure the chain to the rail, and a small flashlight (the kind you wear on your head) to help me see what I was doing (it was night time and the garage door was shut anyway). Oh, and a ladder. Be careful on the ladder!