Craftsman Garage Door Opener drive gear replacemnt
I have and older (probably prior to 1984) model #139.664956 that has stripped the drive gear. Sears Parts Direct indicates the replacement gear kit (4A1425) has been discontinued. The original gear had 24 teeth. E-bay shows lots of individual drive gears and several gear kits. However, all the ones I can find indicate that the drive gear has 32 teeth, is 2 3/4" in diameter and has a 1/2" shaft bore. The old 24 tooth one has the 1/2" shaft bore, but is so badly stripped, I cannot determine the original diameter. Question is: Can I interchange a newer 32 tooth gear for the original 24 tooth gear (my old worm gear looks OK) or must I also change the worm gear to match the pitch of the teeth on the drive gear. Thanks for any advice.