TB 11-6115-741-24
Tier 2 Maintenance Requirements
4.0 During repairs, a new component may be substituted as an alternative to remanufacturing or repairing
the old component.
4.1 Generator Set disassembly The entire generator set shall be disassembled as required to perform the
maintenance required in this section.
4.2 Engine.
4.2.1 The entire engine shall be disassembled and remanufactured in accordance with the OEM
specifications and the requirements specified herein. As each engine NMWR is published, that
engine shall be remanufactured in accordance with its NMWR. Block, head, rods, crankshaft,
camshaft, and other components to be reused after inspection shall be thoroughly cleaned to
remove all contaminants, corrosion and carbon. As an option, a new OEM engine may be
installed.
4.2.2 All wearable items, such as non-metallic hoses, filters, gaskets, o-rings, seals, expansion
plugs, bearings, bushings, piston rings shall be replaced with new items. All screens shall be
cleaned or replaced. All additional parts specified herein and by the OEM to be replaced shall be
replaced. Some of the normally replaced components may be not be available for older engines
no longer in production. If parts availability problems are encountered, please contact CECOM
to discuss alternatives.
4.2.3 The block shall be remanufactured to OEM specifications. The block shall be NDT
inspected by a certified inspector. The block shall be visually inspected for signs of pitting,
gouging, or scoring and dimensionally checked. Resurface the cylinder head mating surface as
required to ensure proper sealing of new head gasket as required. Machine/hone main bore as
required. Blocks with liners shall have all parent bores machined as required. Install new freeze
plugs and cam bearings.
4.2.4 The head shall be remanufactured to OEM specifications. Each head shall be NDT
inspected by a certified inspector. Heads shall be inspected for flatness and resurfaced as required
to ensure proper sealing of new head gasket. Valves and valve seats shall be ground or replaced
then ground. Valves, valve guides and valve springs shall be inspected and tested. Out of
tolerance valve springs shall be replaced. Assemble components and test the valve and valve seat
using a vacuum pump maintaining a minimum of 25 in. HG.
4.2.5 Each connecting rod shall be visibly inspected for damage and if an indication/crack is
possibly observed, the item shall be NDT inspected by a certified inspector. As required, the big
end shall be resized and machined to OEM specifications Pin bushing shall be replaced and sized
to OEM specifications. Each rod shall be inspected for twist and bend dimension as well as
center-to-center length.
4.2.6 Each crankshaft shall be NDT inspected by a certified inspector. Each camshaft shall be
visibly inspected for damage and if an indication/crack is possibly observed, the item shall be
NDT inspected by a certified inspector. Each shall be Rockwell hardness tested as required. Each
shall be dimensionally checked to OEM specifications. All crankshaft fillet areas shall be
