Lincoln F4AZ-9430-B Exhaust Manifold Assembly

Disconnect the battery cable from the negative terminal of the battery. Raise the vehicle and support it securely on jackstands. Working under the vehicle, apply penetrating oil to the exhaust pipe-to-manifold studs and nuts. Remove the nuts that hold the exhaust pipe flange to the exhaust manifold. Unplug the electrical connector for the oxygen sensor. Lower the vehicle and remove the spark plug heat shields, if equipped. First, remove the spark plug heat shield nuts and then remove the shield, and spark plugs. Remove the manifold heat shields, if equipped. On some models, it is necessary to remove the heat shield nuts and the heat shield to gain access to the exhaust manifold bolts - use penetrating oil to make the fasteners easier to remove. Remove the air cleaner assembly and heat stove tube, if equipped. For the right side manifold, remove the Thermactor hardware, if equipped. Remove the automatic transmission fluid dipstick tube, if necessary. For the left side manifold, if it's in the way, remove the engine oil dipstick and tube. For both manifolds, bend back the locking tabs. Some models are equipped with manifold bolt locking tabs -bend these down before removing the bolts - use new locking assemblies on installation, bending the tabs up to lock the bolts in place, if equipped. Remove the mounting bolts and separate the manifold from the head. Use a deep socket to remove the special stud bolts used to retain the spark plug heat shield. Note the locations of the pilot bolts.Check the manifold for cracks and make sure the bolt threads are clean and undamaged. The manifold and cylinder head mating surfaces must be clean before the manifolds are reinstalled - use a gasket scraper to remove all carbon deposits and old gasket material. Position the manifold and gasket, if used, on the head and install the mounting bolts. When tightening the mounting bolts, work from the center to the ends and tighten the bolts in three equal steps. The remaining installation steps are the reverse of removal. Start the engine and check for exhaust leaks.