A support system for an exhaust aftertreatment system for a two-stroke locomotive diesel engine providing a secure mounting of certain components of the exhaust aftertreatment system to the locomotive structure while at the same time allowing for differential thermal expansion (and the resulting physical displacement) of the components. The support system further carries the physical mass of the components of the aftertreatment system while at the same time effectively isolating the aftertreatment system from external loads and forces caused by motions of the locomotive engine and the locomotive frame.