1991- F150 2wd Cylinder E40D Transmission Cooler Lines 5/16" Tube OE Steel 2pc These preformed transmission lines replace the original transmission cooler lines and run from transmission to radiator following the factory routing. Our replacement lines are engineered from factory original lines and CNC manufactured for precision. They include the correct fittings, flares, and protective wrap (where equipped) and are designed to work with factory radiators and components.