I have replaced the starter in my truck 3 times. for the first 2 - 3 weeks it works great, but then it starts to make grinding sounds and takes a lot more effort to start. The last time I replaced the starter, I found that one of the teeth had broken off of the gear in the starter - I know thats not good, but have know idea why this happened. The teeth on the fly wheel are slightly worn on the ends. I need help - i'm getting tired of replacing the starter. Any help would be great.