Careers Career Paths Army MOS 91 Field Series Field Mechanical Maintenance Share PINTEREST Email Print jeep maintenance by Army mechanic. gettys Career Paths US Military Careers Technology Careers Sports Careers Sales Project Management Professional Writer Music Careers Media Legal Careers Government Careers Finance Careers Fiction Writing Careers Entertainment Careers Criminology Careers Book Publishing Aviation Animal Careers Advertising Learn More By Stewart Smith Stewart Smith Author, Strength and Conditioning Specialist, Former Navy SEAL Officer US Naval Academy Stew Smith, CSCS, is a Veteran Navy SEAL Officer, freelance writer, and author with expertise in the U.S. military, military fitness, and its traditions. Learn about our Editorial Process Updated on 06/07/19 Maintaining the operational function of all machines in the arsenal of the Army is the job of this career field. Army MOSs: Mechanical Maintenance Field 91A - M-1 Abrams Tank System Maintainer - The M-1 Abrams tank system maintainer is primarily responsible for supervising and performing maintenance on Abrams tanks. The duties performed by Soldiers in this MOS include performing maintenance on the suspension, steering, hydraulic, auxiliary power, fire extinguisher/suppression and gas particulate systems, and diagnose and troubleshoot malfunctions. 91B - Wheeled Vehicle Mechanic - The wheeled vehicle mechanic is primarily responsible for supervising and performing maintenance and recovery operations on wheeled vehicles and associated items, as well as heavy-wheeled vehicles and select armored vehicles. 91C - Utilities Equipment Repairer - The utilities equipment repairer is responsible for supervising and performing maintenance on utility equipment and special purpose support systems such as refrigeration systems, air conditioning units, and heaters and more. 91D - Power-Generation Equipment Repairer - The power generation equipment repairer performs maintenance on tactical utility, precise power generation sets, internal combustion engines, and associated equipment 91E - Machinist - This specialist is primarily responsible for supervising and performing the fabrication, repair, and modification of metallic and nonmetallic parts. If you need a part, the machinist can make it. The 91W Metal workout has merged to this MOS. 91F - Small Arms/Artillery Repairer - The small arms/artillery repairer is responsible for keeping a wide array of weapons — from small arms to field artillery and large ballistic missiles — operating properly. 91G - Fire Control Repairer - The fire control repairer is responsible for supervising and performing maintenance on combat vehicles, and infantry and artillery fire control systems and equipment and assessing damage and repair. 91H - Track Vehicle Repairer - The track vehicle repairer is primarily responsible for performing maintenance on tracked vehicles and supervising activities that include fuel and electrical system repair and maintenance. 91J - Quartermaster and Chemical Equipment Repairer - The quartermaster and chemical equipment repairer are primarily responsible for supervising or performing maintenance on chemical equipment, quartermaster machinery, forced air-heaters and special purpose equipment. 91K - Armament Repairer - The Armament Repairer is primarily responsible for supervising and performing maintenance and repairs on the mechanisms and systems of tank turrets, tank weapons, fighting vehicles, towed and self-propelled artillery, small arms, and other infantry weapons. 91L - Construction Equipment Repairer - Construction equipment repairers, are responsible for maintaining trucks, bulldozers, power shovels and other heavy equipment that are needed for construction operations. 91M - Bradley Fighting Vehicle System Maintainer - The Bradley fighting vehicle system maintainer handles the maintenance and repair of the M2/M3, A2/A3 Bradley fighting vehicle, the M6 Bradley linebacker air defense vehicle and the M-7 Bradley fire support team vehicle. 91P - Artillery Mechanic - The artillery mechanic is primarily responsible for supervising and performing maintenance and recovery operations of all self-propelled field artillery cannon weapon systems — including automotive, turret, fire control, and chemical protection subsystems. 91W - 91W no longer exits and has seen some changes. Originally 91W was combat medic. Now that is 68W. 91W became a sheet metal worker which has merged MOS with 91E the Machinist. 91X - Maintenance Supervisor - This position is not an entry-level position. After years of moving up the ranks and mastering your craft, you can be in charge and mentors the unit with knowledge and experience gained of an NCO. 91Z - Mechanical Maintenance Supervisor - The mechanical maintenance supervisor supervises, plans, coordinates, and directs the unit, direct support and general support (DS/GS) maintenance of all mechanical equipment.