I did the mechanic to manager thing, tech for 15 or so years then got promoted to service manager, then Branch manager with 2 branches to look after. I did that for 11 years. It was difficult to transition at first, the guys on the floor that used to be your buddies are now your employees. There can be some animosity with some of the techs if they feel you got promoted over them. I ended up leaving that job after a senior management change that I didn't agree with. It is much easier going into a new job as a manager where you don't have any relationship with anyone.