Corrects vehicle deficiencies by removing, repairing, adjusting, overhauling, assembling, disassembling, and replacing major assemblies, sub- assemblies, components, parts, or systems, such as, brakes, hubs, bearings, seals, electrical, air conditioning, fuel, steering, hydraulics; control linkages, clutches, and traction units. Determines the overall mechanical condition of tractors, trailers and associated equipment, diagnoses component malfunctions and initiates repair actions.