As a truck mechanic, you primarily service and repair diesel engine trucks. Your responsibilities include performing routine maintenance on trucks, communicating with truck owners about current and potential issues and suggested repair methods, ordering parts, and repairing components and mechanisms with known problems. You usually work with computer equipment in addition to regular tools that help diagnose vehicle problems. You need training in a program designed for truck mechanics to work in this field and learn your job duties, although some companies provide on-the-job training under the supervision of a senior-level mechanic.