11. 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.
Overhaul is normally the highest degree of maintenance performed by the Army. Overhaul does not normally
return an item to like new condition.
12. 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 (e.g., hours/miles.) considered in classifying Army equipment/components.
B-3. Explanation of Columns in the MAC, Section II
Column (1) Group Number. Column (1) lists Functional Group Code (FGC) numbers, the purpose of which is to
identify maintenance significant components, assemblies, subassemblies, and modules with the Next Higher
Column (2) Component/Assembly. Column (2) contains the names of components, assemblies, subassemblies, and
modules for which maintenance is authorized.
Column (3) Maintenance Function. Column (3) lists the functions to be performed on the item listed in column (2).
(For a detailed explanation of these functions refer to "Maintenance Functions" outlined above).
Column (4) Maintenance Level. Column (4) specifies each level of maintenance authorized to perform each function
listed in column (3), by indicating work time required (expressed as manhours in whole hours or decimals) in the
appropriate subcolumn. This work time figure represents the active time required to perform that maintenance
function at the indicated level of maintenance. If the number or complexity of the tasks within the listed maintenance
function varies at different maintenance levels, appropriate work time figures are to be shown for each level. 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 time in addition to the time required to perform the specific tasks identified for the maintenance
functions authorized in the MAC. The system designations for the various maintenance levels are as follows:
Operator or Crew maintenance
Direct Support Maintenance
Specialized Repair Activity
General Support maintenance