I have two craftsmen garage door openers. 1/2 hp models w/chain drive. Purchased about the same time and both failed approx same time. Decided to open one up and found that the motor was good but that it had cheap nylon gears inside that had the teeth worn off of them..... all this time I have been in contact with the sears store about the problem and the fix to them was obviously buying a new opener. I have only had these openers approx 3 to 4 years and considering I buy Craftsmen because of solid workmanship and materials, I am very disappointed. I would have been nice to open this up and find metal gears that would have held up year after year.