The responsibilities of an assistant mechanic include performing intermediate skilled repair work on automobiles, small engines, and other equipment. In this career, you help the mechanic install and replace various parts on cars, trucks, and tractors. You may also help perform complete tune-ups. Other duties include changing oil and checking batteries, fan belts, filters, tires, wipers, headlights, and more. You are responsible for troubleshooting and fixing heating and air conditioning systems, electrical controls, suspension, and exhaust systems. You help with overhauling and replacing major components like transmissions and engines. You are expected to order the required parts and supplies, help load and unload delivery trucks, tow broken-down vehicles, perform welding services, and offer assistance to other crews.