The stripping of the gear is very common but is also a symptom of an unbalanced door. The opener reversing direction when the door hits the floor is also a sign of an unbalanced door. The springs should not need to be adjusted after only a year. I would take a good look at the remaining door hardware for excessive wear. I think I would replace the gear and then get another door company to check out the door.

Don,
Thanks for the reply, I replaced the gear and sprocket asbm, glad I did as the top sprocket bushing was worn out too! Apparently the springs have a 3 year parts warranty, but not the labor. The service guy adjusted one spring about a quarter turn and that solved the balance problem. He said that's what they do, one spring, if that's not enough, then the other. Is this typical?
Of course he said sometimes they need adjusting after a year, when he installs, he over adjust to reduce that possibilty when they "Wear In".
I'm trying to decide if I want to argue with the office next week?
Thanks,
Joe

Don,
Thanks again for your reply and all your contributions to this website. This is my first garage door and it performed well for eight plus years, with a unknown history as we bought a pre-owned home. Reading through your post and others in the archives, I have learned a lot about doors, openers and maintenance of them. Next time I'll have a different company come out, as you suggested. Hopefully it will be a long time!
Joe