Answer:
A heavy duty mechanic will train for 5 yrs which includes the first pre- apprenticship program.
you will study and require experience with:
diesel and gas engines
transmissions/final drives/rear ends and other gear compilations
electrical wiring and electronics
mechanical and electronic fuel injection
hydraulics
wheeled and tracked systems
air brake systems
welding and oxy acetylene cutting
shop safety and lifting equipment
all in all its a very good profession but one must be detail orientated and dedicated to continuous learning, if not you will fall behind very easily because both the automotive and heavy duty sectors are rapidly changing every year!