Abstract: A transmission pan with integrated heat exchanger for an automobile vehicle includes a transmission pan. A heat exchanger is positioned entirely within transmission pan and is fixed to a bottom inner surface of the transmission pan. The heat exchanger includes a substantially flat surface. The surface includes a first flow port defining a transmission fluid inlet port, and a second flow port defining a transmission fluid outlet port. A cooling header assembly has an inlet header and an outlet header, each fixed to and sealed at an entrance through a wall of the heat exchanger. The inlet header and the outlet header also each penetrate an outer wall of the transmission pan and are each fixed to and sealed where the penetrations of the inlet header and the outlet header contact the outer wall.