41C4220A Gear and Sprocket Assembly

Garage Door Opener Stripped Nylon Gear

Most chain drive garage door openers have a 41c4220A gear and sprocket assembly inside. These gears are a fail safe during operation to prevent serious damage to the motor. Nylon gears have nylon teeth, which strip out during strenuous operation. Failure often occurs due to torsion springs weakening over time or the garage door freezing to the floor. Think of your garage door opener operation as nothing more than getting the process of opening and closing your overhead door started. Garage door torsion or extension springs do most of the heavy lifting. Running your opener with weakened or broken springs puts too much stress on the opener, causing stripped gears.

Ordering Replacement Parts

Replacing the gear and sprocket with part number 41C4220A is an easy process. This part can be found online for a low price of under $35.00 – while most retail garage door stores sell these parts for at least $50.00. The main drive gear is also available without the sprocket as part number 41A2817.  Installation of these gear and sprocket assemblies can be accomplished by anyone with basic handyman skills – or you can have a professional service call for around $100 in labor.

Gear & Sprocket Repair 41C4220A & 41A2817

  • Chamberlain
  • Liftmaster
  • Sears
  • Craftsman

Never run your garage door opener with a broken torsion spring as this puts too much stress on the drive gear. Check out these Signs Of Broken Garage Door Springs. Make sure you grease the nylon gears in your motor annually. Friction can easily cause these parts to overheat since they are made of nylon. Most gears tend to strip during winter months due to the cold weather. The rubber seal on the bottom of your garage door can freeze to the ground. Unknowing homeowners try to open the door and strip out the nylon gears inside the motor. Clear away all snow and debris from the garage door opening during winter months.

  • Grease Nylon Gears Annually
  • Never Run the Opener with Broken Springs
  • Clear Away Ice During Winter
  • Do Not Adjust #48 Chain Too Tight

To prevent damaged to your 41C4220A  or 41A2817 gear grease it annually, especially before winter. This will help prevent it from overheating during strenuous use. During installation be sure not to over tighten your opener chain. Doing so will wear down the teeth on the gear prematurely. During cold winter months clear away all snow and debris from the entrance to your garage. Running the opener with the door frozen to the ground can damage your gear.  Lastly, check to make sure your garage door springs have the proper tension.  Refer to our tutorial, “How to Check Garage Door Balance” for instructions on how to do this.

Garage Door Guide Cal
Hello, I’m Cal – owner of Garage Door Guide LLC    

I write tutorials about garage door repair, installation and maintenance. With over a decade of experience in the overhead door industry I’ve learned a lot and I’d like to share my knowledge with you.

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