Ditto on what has been said. I take my burn in a little longer, normally 30 minutes. Just me, it's probably doesn't need to be that long. I also grab the output wheel during cycling and add some resistance. This is my way to check the gears. I also do one other thing. I put an amp meter in line with the servo and check it's idle current and it's operating current. Check this against specs. A failing servo motor will draw more amps and is a sign of going bad. I don't measure torque either. I just use the manufactures data. Observation is the best preventive measure you can use. Watch and listen to the servos, they will tell you when they start to go bad. When flying, if it doesn't feel right, land and check it. I've seen too many flyers continue to fly when they comment on soemthing feeling different. just use common sense.