a. The scope of maintenance and repair by the crew and other units of the using arms is determined by the availability of suitable tools, availability of necessary parts, capabilities of the mechanics, time available, and the tactical situation. All of these are variable and no exact system of procedure can be prescribed.

25. ALLOCATION OF MAINTENANCE.

a. Indicated below are the maintenance duties for which tools and parts have been provided for the using arm and maintenance personnel. Replacements and repairs which are the responsibility of ordnance maintenance personnel may be performed by using arm personnel when circumstances permit, within the discretion of the commander concerned. Echelons and words as used in this list of maintenance allocations are defined as follows:

First and Second Echelon:
Table III
AR 850–15
Operating organization driver, operator or crew, companies and detachments, battalions, squadrons, regiments, and separate companies and detachments (first and second echelons, respectively).
Third Echelon:
Table III
AR 850–15
Technical light and medium maintenance units, including post and port shops.
Fourth Echelon:
Table III
AR 850–15
Technical heavy maintenance and field depot units including designated post and service command shops.
Fifth Echelon:
Table III
AR 850–15
Technical base units.
Service:
(Including preventive maintenance) par. 24 a (2) and (3) in part AR 850–15
Checking and replenishing fuel, oil, grease, water and antifreeze, air, and battery liquid; checking and tightening nuts and bolts; cleaning.
Service:
(Including preventive maintenance) par. 24 a (2) and (3) in part AR 850–15
Checking and replenishing fuel, oil, grease, water and antifreeze, air, and battery liquid; checking and tightening nuts and bolts; cleaning.
Replace:
Par. 24 a (5)
AR 850–15
To remove an unserviceable part, assembly, or subassembly from a vehicle and replace it with a serviceable one.
Repair:
Par. 24 a (6) in part
AR 850–15
To restore to a serviceable condition, such parts, assemblies or subassemblies as can be accomplished without completely disassembling the assembly or subassembly, and where heavy riveting, or precision machining, fitting, balancing, or alining is not required.
Rebuild:
Par. 24 a (6)
AR 850–15
Consists of stripping and completely reconditioning and replacing in serviceable condition any vehicle or unserviceable part, subassembly, or assembly of the vehicle, including welding, riveting, machining, fitting, alining, balancing, assembling, and testing.
Reclamation:
AR 850–15 Par. 4 (c) in part CIR. 75, dated 16 March ’43
Salvage of serviceable or economically repairable units and parts removed from vehicles, and their return to stock. This includes the process which recovers and/or reclaims unusable articles or component parts thereof and places them in a serviceable condition.

NOTES: (1) Operations allocated will normally be performed in the echelon indicated by X.
(2) Operations allocated to the third echelon as indicated by E may be performed by these units in emergencies only.
(3) Operations allocated to the fourth echelon by E are normally fifth echelon operations. They will not be performed by the fourth echelon, unless the unit is expressly authorized to do so by the chief of the service concerned.

ECHELONS
CLUTCH2nd3rd4th5th
Bearings, clutch release—replaceX
Clutch—replace and/or repair (reline) X
Hub, clutch—replace X
Hub, clutch—repair X
Sprocket assembly, clutch—replace X
Sprocket assembly, clutch—repair X
CONTROLS AND LINKAGE
Controls and linkage—service and/or replaceX
Controls and linkage—repair X
ELECTRICAL GROUP
Battery—service (recharge) and/or replaceX
Battery—repair X
Battery—rebuild EX
Cables, battery—replace and/or repairX
Coil, ignition—replaceX
Head, speedometer—replaceX
Head, speedometer—repair X
Head, speedometer—rebuild X
Horn assembly—replaceX
Horn assembly—repair X
Light assemblies—service and/or replaceX
Light assemblies—repair X
Panel, instrument—replaceX
Panel, instrument—repair X
Switch assemblies—replaceX
Switch assemblies—repair X
Wiring—replaceX
ENGINE
(V–45″–Twin Engine)
Bearings, main—replace EX
Bearings, connecting rod—replace EX
Breaker assembly, circuit—replaceX
Breaker assembly, circuit—repair X
Breaker assembly, circuit—rebuild X
Carburetor—replaceX
Carburetor—repair X
Carburetor—rebuild X
Cleaner, air—service and/or replaceX
Cleaner, air—repair X
Cleaner, air—rebuild X
Cylinder assembly—replace X
Cylinder assembly—repair X
Cylinder assembly—rebuild (recondition) EX
Condenser—replaceX
Engine assembly—replace*[4]X
Engine assembly—repair X
Engine assembly—rebuild EX
Gasket, cylinder head—replaceX
Gears, timing—replace EX
Generator assembly—replaceX
Generator assembly—repair X
Generator assembly—rebuild X
Head, cylinder—replace and/or repair X
Lines and connections—replaceX
Lines and connections—repair X
Pistons, rings and pins assembly—replace EEX
Plug, spark—replaceX
Points, circuit breaker—service and/or replaceX
Pump assembly, feed—replaceX
Pump assembly, feed—repair X
Pump assembly, feed—rebuild X
Pump assembly, oil—replaceX
Pump assembly, oil—repair X
Pump assembly, oil—rebuild X
Pump assembly, oil scavenger—replace and/or repair X
Pump assembly, oil scavenger—rebuild X
Rod, connecting—replace and/or rebuild (recondition) XX
Sprocket, engine—replaceX
Strained gasoline—replace and/or repair X
Valves—serviceX
EXHAUST GROUP
Muffler and exhaust pipe—replaceX
Muffler and exhaust pipe—repair X
MISCELLANEOUS
Bars, safety—replaceX
Bars, safety—repair X
Boxes, ammunition, battery and tool—replaceX
Boxes, ammunition, battery and tool—repair X
Carriers, luggage and scabbard—replaceX
Carriers, luggage and scabbard—repair X
Frame—replace and/or rebuild EX
Guards, mud—replaceX
Guards, mud—repair X
Plate, skid—replaceX
Plate, skid—repair X
Saddle—replaceX
Saddle—repair X
Saddle—rebuild X
Springs, saddle post—replaceX
Tank, fuel—replaceX
Tank, fuel—repair X
Tank, oil—replaceX
Tank, oil—repair X
SUSPENSION (FRONT)
Bars, handle—replaceX
Bars, handle—repair X
Damper, steering—replaceX
Drum, brake—replace X
Fork, front assembly—replaceX
Fork, front assembly—repair X
Fork, front assembly—rebuild X
Fork, spring—replaceX
Fork, spring—repair X
Fork, spring—rebuild X
Plate, rocker—replaceX
Plate, rocker—repair X
Shoe assembly, brake—service and/or replaceX
Shoe assembly, brake—repair (reline) X
Springs, cushion and rebound—replaceX
SUSPENSION (REAR)
Chains, all—replace and/or repairX
Drum, brake, rear—replace X
Guards, chains—replaceX
Guards, chains—repair X
Shoe assemblies, brake—service and/or replaceX
Shoe assemblies, brake—repair (reline) X
Sprocket, rear—replace X
Wheels—replaceX
Wheels—repair X
Wheels—rebuild EX
TIRES
Casings and tubes—replaceX
Casings—repair EX
Tubes, inner—repairX
TRANSMISSION
Spring, kick starter—replaceX
Sprocket, transmission countershaft—replaceX
Starter, kick—replaceX
Starter, kick—repair X
Transmission—replace*[4]X
Transmission—repair X
Transmission—rebuild EX
VEHICLE ASSEMBLY
Motorcycle—serviceX
Motorcycle—rebuild (with serviceable unitassemblies) XE

4 The second echelon is authorized to remove and reinstall items marked by an asterisk. However, when it is necessary to replace an item marked by an asterisk with a new or rebuilt part, subassembly or unit assembly, the assembly marked by an asterisk may be removed from the vehicle by the second echelon only after authority has been obtained from a higher echelon of maintenance.


Section VIII
SECOND ECHELON PREVENTIVE MAINTENANCE