Technical: The large, main gear has 32 teeth and is 2 3/4" x 1/2" wide, with a 1/2" bore (sizes are approximate). You MUST apply a low temperature lithium grease (included) to each tooth of the new gear or it will shred within days.
Compatibility: Works with ALL 1/3 HP, 1/2 HP and 3/4 HP chain and belt drive garage door openers manufactured from 1984 to the present for these manufacturers: Liftmaster, Sears Craftsman, Chamberlain, Garage Master, Master Mechanic and Wayne Dalton. REPLACEMENT GEARS FOR LIFTMASTER CRAFTSMAN CHAMBERLAIN GARAGE DOOR OPENER MODELS MANUFACTURED PRIOR TO 1984 ARE NO LONGER AVAILABLE.
Fits these Chamberlain Models: 1100, 1200, 2100, 2200, 4100, 4200, 4893OD, 5100, 6200, 710WHC, 711WHC, 7200, 7220, 7320, 7420, 7520D, 8100, 8100M, 8200, 9200, CG40, CG40D, CG42D, CSO, HD200D, HD600, PD100, PD200, PD210, PD210D, PD212, PD212D, PD600, PD610, PD610D, PD612K, PD612KLD, PD752, PD752D, PD758D, PD758S, WD822K, WD822KD, WD822KS, WD912K, WD912KS, WD922K.
Raynor Navigator 2245RGD, Ultra 2595RGD, Endeavor 2585RGD, Aviator 2280RGD, Pilot 2265RGD. Also used for Wayne Dalton opener models 100 to 320.
Fits these Liftmaster Models: 985, 1240, 1240R, 1245, 1245R, 1245LK, 1246, 1246R, 1250, 1255, 1255R, 1256, 1256R, 1260, 1260LK, 1265, 1270, 1280, 1280R, 1345, 1346, 1356, 215WD, 220WD, 2245, 2255, 2265, 2565, 2280, 2575, 2580, 2585, 2595, 315WD, 320WD, 3245, 3255, 3265, 3280, 3575, 3585, 3595, ATS211, ATS211R, ATS211X and ATS2113X.
Fits these Sears Craftsman models: 139.53990, 139.53992, 139.53914, 139.53985, 139.53930,
139.5365, 139.53964, 139.53646, 139.53660, 139.53920, 139.53939, 139.184050, 139.18803, 139.18805, 139.18814, 139.18830, 139.53603, 139.53629SRT, 139.53629SRT1, 139.53674SRT2, 139.18850 and 139.18851. Only the most common models are listed here are listed here.
If you don't see your Sears Craftsman garage door opener model listed here, please click here for our Sears Craftsman Garage Door Opener Gear Compatibility Chart. If you still don't see your model listed here, please
email us and we will let you know which gear is compatible with your opener.
Includes: 3 replacement heavy duty main drive gears and 3 tubes of low temperature lithium grease.
Miscellaneous: If you need or wish to also replace the sprocket and shaft, please see part number
41C4220A.
Click here to view this gear and lubricant kit that is also available in a value-priced Contractor 6 Pack.Click here to read our How To Article on replacing your garage door opener gear
Garage Door Opener Replacement Gears 
Good value option 