TM 9-4120-407-14
B-2. MAINTENANCE FUNCTIONS. (Cont)
j. Overhaul. That maintenance effort (service/actions) prescribed to restore an item to a completely
serviceable/operational condition as prescribed 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
material 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 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 Functions. Column 3 lists the functions to be performed on the item listed in
column 2. (For detailed, explanation of these functions, see paragraph B-2.)
d. Column 4. Maintenance Category. Column 4 specifies, by the listing of a work time figure in the
appropriate subcolumn( the category of maintenance authorized to perform the function listed in Column
3. This figure represents the active time required to perform the maintenance function at the indicated
level of maintenance. If the number or complexity of the tasks within the listed maintenance functions vary
at different maintenance categories, appropriate work time figures will be shown for each category. The
work time figure represents the average time required to restore an item (assembly, subassembly, component,
module, end item, or system) to a serviceable condition under typical field operating conditions. This time
includes preparation time (including any necessary disassembly/assembly time), troubleshooting/fault
location time, and quality assurance/quality control time in addition to the time required to perform the
specific tasks identified for the maintenance functions authorized in the maintenance allocation chart. The
symbol designations for the various maintenance categories are as follows:
C ...........................................
Operator or Crew
O..........................................
Unit
F .............................................
Direct Support Maintenance
H .......................................
General Support Maintenance
D......................................
Depot Maintenance
e. Column 5. Tools and Equipment. Column 5 specifies, by code, those common tool sets (not individual
tools) and special tools, TMDE, and support equipment required to perform the designated function.
f. Column 6. Remarks. Column 6 contains a note number which shall correspond to the notes contained in
Section IV.
l
Services-inspect, test, service, adjust, aline, calibrate, and/or replace.
2
Fault locate/troubleshoot-The process of investigating and detecting the cause of the equipment
malfunctioning; the act of isolating fault within a system or unit under test (UUT).
3
Disassemble/assemble-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.
4
Actions-welding, grinding, riveting, straightening, facing, remachinery, and/or resurfacing.
B-2