TM 5-3810-306-20
Install. To setup for use in an operational environment such as an replacement, site, or vehicle.
Replace. To replace unserviceable items with serviceable like items.
Repair. Those maintenance operations necessary to restore an item to serviceable condition through correction of
material damage or a specific failure. Repair may be accomplished at each category of maintenance.
Overhaul. Normally, the highest degree of maintenance performed by the Army in order to minimize time work in process
is consistent with quality and economy of operation. It consists of that maintenance necessary to restore an item to
completely serviceable condition as prescribed by maintenance standards in technical publications for each item of
equipment. Overhaul normally does not return an item to like new, zero mileage, or zero hour condition.
Rebuild. The highest degree of material maintenance. It consists of restoring equipment as nearly as possible to new
condition in accordance with original manufacturing standards. Rebuild is performed only when required by operational
considerations or other paramount factors and then only at the depot maintenance category. Rebuild reduces to zero the
hours or miles the equipment, or component thereof, has been in use.
EXPLANATION OF COLUMNS IN SECTION II
Group Number, Column 1. The assembly group is a numerical group assigned to each assembly in a top down
breakdown sequence. The applicable assembly groups are listed on the MAC in disassembly sequence beginning with
the first assembly removed in a top down disassembly sequence.
Component/Assembly, Column 2. This column contains the names of components, assemblies and subassemblies.
Maintenance Function, Column 3. This column lists the various maintenance functions to be performed on items listed in
column 2.
Maintenance Category, Column 4. Column 4 specifies, by the listing of a "work time": figure in the appropriate
subcolumn(s), the lowest level 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 category of maintenance. If the
number or complexity of the tasks within the listed maintenance function vary at different maintenance categories,
appropriate "work time" figures will be shown for each category. The number of man-hours specified by 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,
troubleshooting 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 MAC.
B-2
