A combination heat exchanger comprises a first heat exchanger assembly and a second heat exchanger assembly. The first heat exchanger assembly includes a first end tank, a second end tank, and a first heat exchanger core including a plurality of first heat exchanger tubes extending longitudinally in a first direction. The second heat exchanger assembly includes a third end tank, a fourth end tank, and a second heat exchanger core including a plurality of second heat exchanger tubes extending longitudinally in the first direction. A first coupling includes a first attachment portion rigidly coupled to the first end tank, a second attachment portion rigidly coupled to the third end tank, and a thermal expansion portion extending between the first attachment portion and the second attachment portion. The first coupling allows for relative translation between the first end tank and the third end tank in the first direction.