ARMY TM 9-2815-253-24
AIR FORCE TO 38G1-93-2
MARINE CORPS TM 2815-24/3
MAINTENANCE ALLOCATION CHART (MAC)
This section provides a general explanation of all maintenance and repair functions authorized at various
The Maintenance Allocation Chart (MAC) in SECTION II designates overall authority and responsibility for the
performance of maintenance functions on the diesel engine and its components. The application of the maintenance
functions to the engine components will be consistent with the capacities and capabilities of the designated maintenance
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 functions.
B-2. MAINTENANCE FUNCTIONS. Maintenance functions will be limited to and defined as follows:
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).
Test. To verify serviceability by measuring the mechanical, pneumatic, or electrical characteristics of an item
and comparing those characteristics with prescribed standards.
Service. Operations required periodically to keep an item in proper operating condition; i.e., to clean (include
decontaminate, when required), to preserve, to drain, to paint, or to replenish fuel, lubricants, chemical fluids, or gases.
Adjust. To maintain or regulate, within prescribed limits, by bringing into proper or exact position, or by setting
the operating characteristics to specified performance.
Align. To adjust specified variable elements of an item to bring about optimum or desired performance.
Calibrate. To determine and cause corrections to be made or to be adjusted on instruments or Test, Measuring,
and Diagnostic Equipment (TMDE) 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
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.
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.
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.
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.
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.
Change 1 B-1