The general purpose of the occupational analysis is to provide workable, basic information dealing with the many and varied duties performed in the diesel truck mechanic occupation. The document opens with a brief introduction followed by a job description. The bulk of the document is presented in table form. Thirteen duties are broken down into a number of tasks and for each task a two-page table is presented, showing on the first page: tools, equipment, materials, objects acted upon; performance knowledge (related also to decisions, cues and errors); safety--hazard; and on the second page: science; math--number systems; and communications (performance modes, examples, and skills and concepts). The duties include maintaining and repairing engines, fuel systems, electrical systems, cooling systems, brake systems, driveline, steering systems, suspension, exhaust systems, hydraulic systems, refrigeration and air conditioning systems, chassis components, and cab and accessories. (BP)