Diagnoses problems and performs tractor-trailer repairs/part replacement including but not limited to diesel engines, brakes, rear-ends, clutches, air conditioners, radiators, diesel engine injectors, water pumps, and wheel bearings. Must be able to perform the following physical activities: Climbing, balancing, stopping, kneeling, crouching, crawling, reaching, standing, walking, pushing, pulling, lifting, fingering, grasping, feeling, talking, hearing, and repetitive motion.