This exhaust manifold gasket seals the joint between the exhaust manifold and the cylinder head on the host tractor. It prevents exhaust gas from escaping at the connection, which would otherwise cause a loss of back pressure and a drop in engine performance. The gasket is exposed to high thermal cycling and combustion byproducts; a failed gasket produces a ticking or puffing sound under load and may leave soot traces around the manifold flange. On replacement, clean both sealing surfaces thoroughly and tighten the manifold bolts to the specified torque in the correct sequence.