Replacement for Liftmaster 41c4220a Gear and Sprocket Kit fits Chamberlain, Sears, Craftsman 1/3 and 1/2 HP Chain Drive Models

I bought this product as my sprocket in a Lift Master 3255 snapped off....I replaced the main gear shaft with the sprocket attached and re-assembled the opener. The chain traveled approximately 24 inches and stopped, it was trying to close the door that was already closed. The MOST important thing to do whenever the chain breaks or the sprocket breaks off, is make certain the opener and the garage door are in the same cycle. To do so, before you re-attach your chain, run the opener, being certain that the garage door and opener are in sync; in other words the door is closed and the opener is also in the closed position , then attach the chain. The kit is great however I spent many hours trying to figure out the "cycle" issue thinking it was something else.....I also replaced the RPM sensor, the capacitor and the logic board which was not the problem. At least I have all new parts in this 3255 and it now works great. I finally realized this from a you tube video and hope this can help others with this unit.

Sprocket kit arrived on time and as ordered. Replacement was fairly straightforward after seeing the many repair videos that are available online. This is a moderate DYI project, but I would definitely recommend viewing some of the videos if you don't have prior experience, as there are some helpful tips to know about in advance. The repairs were successful and well worth the price versus calling in a garage door repairman.

This had everything I needed to get my old sears garage door opener working again. Easy to replace the parts, and yyyyeee hhhaaawwr the door is back to assisted openings.I was tired of manually opening this big old heavy steel door.

It is a very complete kit. Some items I didn't use as my bushings are good. Many just replace the worm wheel but I replaced the worm gear while I was at it. I likely could have got away with just the wheel.I'm going to buy a second kit for my other door to have on hand.

It’s easy. Don’t buy just the gear. I only use the main assembly. I messed with getting the pin out of the old one for a bit, but it just wasn’t worth it for the price of this kit. I already had some taps with the pilot drill attached to the tip from Amazon. They cost about as much as the kit, but they’re great to have around if you don’t lose them. they’re only meant for a quick small project not repetitive use use them two or three times and it was worth it just for a convenience. You should try Mark where the shuttle is on your track. I didn’t count the teeth on the replacement…. But after I had it all set up, I had to loosen the chain again and move it so that it was within the range of the adjustments for up and down. Really not that big of a deal. The holes really should already be tapped though it only takes four or five minutes tops..

had a 1998 Liftmaster and it works perfect - better than old one - thank you Amazon for carrying this

WOW .The Parts came in ONE day. Fast fast service. Very happy, parts look dead on. Will install them this weekend.

Listing and the pictures of the parts shown on Amazon are exactly as shown! I used it to fix my Craftsman model 13953990. Note that it DOES need slight modification to fit it. I had to grind off the edge of the housing that holds the chain drive gear. It needs a flat edge to fit. Also note the chain drive gear is SMALLER, but works fine since this gear reduction gives it more lift power, but makes it slightly slower to open. Note this gear difference requires to you adjust the door OPEN/CLOSE switches due to the gear making more revolutions, the Open/close switch positions are farther apart. I suggest placing door chain at the door open position then set switches on that worm gear to have more travel between them. I also noticed that due to smaller gear, the chain rubs more on the chain guide.