Repair clutches, transmission systems, differentials, air compressors, pumps, filter units, starting engines, generators, governors, hydraulic systems, air systems, heating and cooling systems, steering systems, electrical systems, and associated components. As a condition of employment, candidates and incumbents must favorably complete a personnel security investigation, drug testing, medical exam and respiratory screening, and must meet and maintain personnel suitability and reliability requirements established by 29 CFR and Army Regulations: AR 190-11, AR 190-13 and DOD Contractors Safety Manual 4145.26.