A power train system comprising: a source of rotational energy including a mounting surface having an opening therethrough; a combined power take-off and synchronized clutch assembly that is rotatably driven by the source of rotational energy; and characterized by a hydraulic pump that is connected to and selectively rotatably driven by the combined power take-off and synchronized clutch assembly; and a hydraulically driven accessory that is connected to and operated by the hydraulic pump; wherein the combined power take-off and synchronized clutch assembly includes: a power take-off portion including: a housing having a mounting surface that is adapted to be secured to the mounting surface provided on the source of rotational energy, the mounting surface of the housing of the power take-off portion having an opening therethrough, an input mechanism including an input gear that is rotatably supported on the housing of the power take-off portion and that has a portion that extends outwardly through the opening provided through the mounting surface of the housing of the power take-off portion and is adapted to extend within and be rotatably driven by the source of rotational energy, and an output mechanism that is rotatably driven by the input mechanism; and a synchronized clutch portion that selectively connects the output mechanism of the power take-off portion to an output shaft that is adapted to be connected to the rotatably driven hydraulic pump that, in turn, is adapted to operate the hydraulically driven accessory. a source of rotational energy including a mounting surface having an opening therethrough; a combined power take-off and synchronized clutch assembly that is rotatably driven by the source of rotational energy; and characterized by a hydraulic pump that is connected to and selectively rotatably driven by the combined power take-off and synchronized clutch assembly; and a hydraulically driven accessory that is connected to and operated by the hydraulic pump; wherein the combined power take-off and synchronized clutch assembly includes: a power take-off portion including: a housing having a mounting surface that is adapted to be secured to the mounting surface provided on the source of rotational energy, the mounting surface of the housing of the power take-off portion having an opening therethrough, an input mechanism including an input gear that is rotatably supported on the housing of the power take-off portion and that has a portion that extends outwardly through the opening provided through the mounting surface of the housing of the power take-off portion and is adapted to extend within and be rotatably driven by the source of rotational energy, and an output mechanism that is rotatably driven by the input mechanism; and a synchronized clutch portion that selectively connects the output mechanism of the power take-off portion to an output shaft that is adapted to be connected to the rotatably driven hydraulic pump that, in turn, is adapted to operate the hydraulically driven accessory. a power take-off portion including: a housing having a mounting surface that is adapted to be secured to the mounting surface provided on the source of rotational energy, the mounting surface of the housing of the power take-off portion having an opening therethrough, an input mechanism including an input gear that is rotatably supported on the housing of the power take-off portion and that has a portion that extends outwardly through the opening provided through the mounting surface of the housing of the power take-off portion and is adapted to extend within and be rotatably driven by the source of rotational energy, and an output mechanism that is rotatably driven by the input mechanism; and a housing having a mounting surface that is adapted to be secured to the mounting surface provided on the source of rotational energy, the mounting surface of the housing of the power take-off portion having an opening therethrough, an input mechanism including an input gear that is rotatably supported on the housing of the power take-off portion and that has a portion that extends outwardly through the opening provided through the mounting surface of the housing of the power take-off portion and is adapted to extend within and be rotatably driven by the source of rotational energy, and an output mechanism that is rotatably driven by the input mechanism; and a synchronized clutch portion that selectively connects the output mechanism of the power take-off portion to an output shaft that is adapted to be connected to the rotatably driven hydraulic pump that, in turn, is adapted to operate the hydraulically driven accessory.