★★★★★
Saved me $400 in service-call fees. My 1996 Liftmaster sounded like a coffee grinder. Followed the included instructions and a YouTube video — back in business in under an hour.
Liftmaster
41C4220A Gear and Sprocket Replacement Kit
The complete drive-end repair kit for Chamberlain, Liftmaster, and Sears Craftsman chain-drive openers built 1984–2000. When your motor runs but the chain doesn't move — or moves with a grinding sound — the helical gear has stripped. This kit replaces every wear part inside the gear case.
$28.95
● In stock — ships next business day
🛟 Free technical support
📄 Installation & FAQ
- ModelLiftmaster 41C4220A
- TypeGear & sprocket replacement kit
- FitsChain-drive openers built 1984–2000
- Compatible brandsLiftmaster · Chamberlain · Sears Craftsman
- Service greaseIncluded (lithium-based)
- Repair time45–60 minutes (typical DIY)
In the box
- Helical (screw) gear
- Drive gear with sprocket
- Worm gear
- Two roll pins
- Spring washer & thrust washer
- Bearing plate & retaining ring
- Tube of service grease
- Step-by-step instructions
Fits these openers
If your model isn't listed, send us a photo and we'll verify before you buy.
Liftmaster chain-drive
1245
1255
1265
1280
2110
2245
2255
2265
2280
3220
3245
3255
3265
3280
3850
Chamberlain
HD200
HD400
HD600
HD700
HD900
HD950
Sears Craftsman
139.53641
139.53661
139.53675
139.53985
139.53990
139.5399
139.53991
If your opener is a screw-drive rather than chain-drive, you need the 41A2817 worm-and-drive kit instead. Not sure? Look up at the rail above your door — chain-drive openers have a visible bicycle-style chain; screw-drives have a long threaded steel rod.
When to replace your gears
Three diagnostic signs that this kit will fix:
- Motor runs but the chain doesn't move — the helical gear teeth have sheared off.
- Loud grinding or clattering during operation — gear teeth are worn but still partially engaging.
- Door reverses partway up or stops moving entirely — partial gear failure under load.
What customers say
★★★★★
The grease included was the difference. Tried this kit from another vendor without grease and it failed in two months. The OEM kit with proper lithium grease has been quiet for three years.