TM 9-2330-231-14&P
B-2. MAINTENANCE FUNCTIONS-CONTINUED.
f. Calibrate. To determine and cause corrections to be made or 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
compared.
g. 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.
h. 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 third position code of the SMR code.
i. Repair. The application of maintenance services1, including fault location/troubleshooting2, removal/installation, and
disassembly/assembly procedures 3 and maintenance actions 4 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.
j. 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.
k. 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.
B-3. EXPLANATION OF COLUMNS IN THE MAC, SECTION II.
a. Column 1, Group Number. Column 1 lists functional group code numbers, the purpose of which is to identify
maintenance significant components, assemblies, subassemblies, and modules with the next higher assembly. End item
group number shall be "00".
b. Column 2, Component/Assembly. Column 2 contains the names of components, assemblies, subassemblies, and
modules for which maintenance is authorized.
c. Column 3, Maintenance Function. Column 3 lists the functions to be performed on the item listed in column 2. See
paragraph B-2 for a detailed explanation of these functions.
1Services-inspect, test, service, adjust, aline, calibrate, and/or replace.
2Fault locating/troubleshooting-process of investigating and detecting the cause of equipment malfunctioning; the act of
isolating a fault within a system or unit under test (UUT).
3Disassembly/assembly-encompasses the step-by-step taking apart (or breakdown) of a spare/functional group coded
item to the level of its least componency identified as maintenance significant (i.e., assigned an SMR code) for the category
of maintenance under consideration.
4Actions-welding, grinding, riveting, straightening, facing, remachinery, and/or resurfacing.
B-2