Receives on-the-job training to inspect, repair and overhaul complex hydraulic and electrical systems; Receives on-the-job training involved in the repair of various specialized mechanical parts or equipment such as crawlers tracks and drivers, winches, bulldozer blades, scoops, excavating and loading bucket chains, power take-off and control mechanisms, centrifugal pumps, ladder and articulating booms, conveyor belts, etc. Diagnoses motor knocks, noises, and other mechanical failures, and under general supervision, disassembles diesel or gasoline engines; Under general supervision, inspects, removes, repairs, and replaces such parts as injection valves, cylinder heads, cylinder sleeves, pistons, rings, connecting rods, bearings, gaskets, etc.