Abstract: A vehicle cab noise suppressing system includes a cab interior panel having an opening exposed to acoustic noise in the cab, an acoustic resonator chamber, and a conduit communicating the resonator chamber to the opening. The resonator chamber is formed by a plurality of walls which are spaced apart from the interior panel and which are formed by a second panel. A third panel cooperates with the walls to enclose the resonator chamber. The chamber volume and the diameter and length of the conduit are chosen so as to acoustically tune the chamber to a noise frequency in the cab and thereby reduce noise in the cab.

Abstract: A vehicle cooling package has a fan shroud mounted to a heat exchanger assembly. A diverter plate is mounted adjacent to the shroud and spaced therefrom with a fan interposed therebetween. A diverting surface of the shroud and the diverter plate are angled from the axis of the fan when the shroud and plate are assembled to the vehicle. A vehicle hood has upper and side surfaces each having air discharge apertures corresponding with the space between the diverting surface and the diverter plate when the hood is closed. The diverting surface and the diverter plate both extend fully to the hood assembly when the hood is closed. The angles of the diverting surface and the diverter plate closely match a natural discharge angle of the fan, so that air is discharged from the fan at a high velocity from under the hood through the air discharge apertures.