MAINTENANCE FUNCTIONS (continued).
Calibrate. To determine the accuracy of and cause corrections or adjustments to be made on instruments or
test, measuring, and diagnostic equipment (TMDE) used in precision measurement. Calibration 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.
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 end Item 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 third position of the source, maintenance, and recoverability (SMR)
Repair. To apply 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 any specific damage, fault, malfunction, or failure in a part, subassembly, module (component
or assembly), end Item, or system.
Overhaul. To perform that maintenance effort (service/action) required to restore an item to a completely
serviceable/operational condition as required by maintenance standards in an appropriate technical publication
(e.g., depot maintenance work requirement). Overhaul is normally the highest degree of maintenance performed
by the Army. Overhaul does not normally return an item to like-new condition.
Rebuild. To perform 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 (e.g., hours, miles) considered In classifying Army equipment/components.
EXPLANATION OF COLUMNS IN SECTION II, MAINTENANCE ALLOCATION CHART
FOR ENGINE ASSEMBLY, DIESEL, HATZ 2 G 40.
(1) Group Number. Column 1 lists functional group code numbers, whose purpose is to identify maintenance-
significant components, assemblies, subassembies, and modules with the next higher assembly. The end Item
group number is "00."
(2) Component/Assembly. Column 2 contains the names of components, assemblies, subassemblies, and
modules for which maintenance is authorized.
(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 para B-2.)
(4) Maintenance Level. Column 4 specifies, by the listing of a work-time figure in the appropriate subcolumn(s),
the level of maintenance authorized to perform the function listed in Column 3. This 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 will 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