MAINTENANCE ALLOCATION CHART (MAC)
This section provides a general explanation of all maintenance and repair functions authorized at various maintenance levels.
The maintenance allocation chart for the turntable used in the M1064A3 is in TM 9-1015-232-23.
The Maintenance Allocation Chart (MAC) in Section II designates overall authority and responsibility for the performance of
maintenance functions on the identified end item or component. The application of the maintenance functions to the end item
or component will be consistent with the capacities and capabilities of the designated maintenance levels.
Section III lists the tools and test equipment (both special tools and common tool sets) required for each maintenance function
as referenced from Section II.
Section IV contains supplemental instructions and explanatory notes for a particular maintenance function.
Section V. The MAC for the mounts and turntables used on the M1064A3 for the M121, 4.7 inch, 120-mm mortar is in TM
9-1015-250-23. The MAC for the M157 Pulse Jet Generator set used in M1059A3 is in TM 3-1040-279-12&P. The MAC for
the M901A3 Turret is covered in TM 9-2350-259-20. The MAC for the M981A3 Turret and Communication Equipment is
covered in TM 9-2350-266-20. The MAC for the M1068A3 Common Hardware System (CHS) is covered in TM
11-7010-256-12. The MAC for the M1068A3 Modular Command Post System (MCPS) is covered in TM
10-5410-229-13&P. The MAC for Personnel Heaters is covered in TM 9-2540-205-24&P.
Maintenance functions will be limited to and defined as follows:
(1) Inspect. To determine the serviceability of an item by comparing its physical, mechanical, and/or electrical
characteristics with established standards through examination (e.g., by sight, sound, or feel).
(2) Test. To verify serviceability by measuring the mechanical, pneumatic, hydraulic, or electrical characteristics of an
item and comparing those characteristics with prescribed standards.
(3) Service. Operations required periodically to keep an item in proper operating condition, i.e., to clean (includes
decontaminate, when required), to preserve, to drain, to paint, or to replenish fuel, lubricants, chemical fluids, or
(4) Adjust. To maintain or regulate, within prescribed limits, by bringing into proper or exact position or by setting the
operating characteristics to specified parameters.
(5) Align. To adjust specified variable elements of an item to bring about optimum or desired performance.
(6) Calibrate. To determine and cause corrections to be made or to be adjusted on instruments or test, measuring, and
diagnostic equipment used in precision measurement. Consists of comparisons of two instruments, one of which is
a certified standard of known accuracy, to detect and adjust any discrepancy in the accuracy of the instrument being
(7) Remove/Install. To remove and install the same item when required to perform service or other maintenance
functions. Install may be the act of emplacing, seating, or fixing into position a spare, repair part, or module
(component or assembly) in a manner to allow the proper functioning of an equipment or system.
(8) Replace. To remove an unserviceable item and install a serviceable counterpart in its place. Replace is authorized
by the MAC and is shown as the 3rd position code of the SMR code.
(9) Repair. The application of maintenance services, including fault location/troubleshooting, removal/installation, and
disassembly/assembly procedures, and maintenance actions to identify troubles and restore serviceability to an item
by correcting specific damage, fault, malfunction, or failure in a part, subassembly, module (component or
assembly), end item, or system.
(10) Overhaul. That maintenance effort (service/action) prescribed to restore an item to a completely serviceable/
operational condition as required by maintenance standards in appropriate technical publications (i.e., DMWR).
Overhaul is normally the highest degree of maintenance performed by the Army. Overhaul does not normally return
an item to like-new condition.
(11) Rebuild. Consists of those services/actions necessary for the restoration of unserviceable equipment to a like-new
condition in accordance with original manufacturing standards. Rebuild is the highest degree of materiel
maintenance applied to Army equipment. The rebuild operation includes the act of returning to zero those age
measurements (hours/miles, etc.) considered in classifying Army equipment/components.