In larger shops, they may specialize in one area. They may work only with electrical systems, transmissions, brakes, or engines. Some mechanics also work on diesel-powered automobiles. Others work on a variety of other diesel-powered equipment. This equipment includes electric generators and compressors and pumps used in irrigation systems and oil well drilling.
Most diesel mechanics work on heavy trucks used in industries.
This includes mining and construction, and private and commercial trucking lines. Mechanics who work for organizations that maintain their own vehicles may spend much time doing preventive maintenance. The occupation of Truck and Heavy Equipment Mechanics includes the specialty of Subway Car Mechanics. For more information on this specialty, see the occupation statement for Subway Car Mechanics. Truck and Heavy Equipment Mechanics is in the Mechanical Repair and Precision Crafts Career Cluster.