TMC0018 is a crossflow charge air cooler for Mack trucks.
The core measures 28.5" high by 25.4375" wide, 2.8125" deep. It has a 4.125" inlet at the flanged left and a 4.125" outlet at the flanged right. There is no integral oil cooler and no filler neck.
It replaces 30 OEM and aftermarket numbers, among them MAC17304, MAC17304R, 621CA113. Searching any one of them will find this part.
On charge air coolers the inlet and outlet positions and the boot diameters matter as much as the core. A cooler that fits the opening but presents its connections on the wrong side will not plumb up.
