Issue link: https://www.e-digitaleditions.com/i/1547091
By Alex Wocking, A&W Tractor, Cecil This article covers the replacement of the manifold gasket on WC, WD, WD45, D17, 170, 175 gas tractors. STEP 1: To replace the manifold gasket, first disconnect the battery. Then, remove the hood, muffler and carburetor. The carburetor can remain hooked to the choke and throttle linkage and set down between the frame rail and the engine block, but be sure to cover the carb with a rag to prevent contamination from dirt and such while working above it. STEP 2: Remove the six nuts that hold the manifold to the cylinder head. (Pay special attention to the studs as the nuts are loosened. If the studs unscrew out of the head instead of the nut coming off the stud, you may need to drain the coolant from the engine. Some of the manifold studs are screwed into a through hole that is drilled into the coolant passage in the head.) After removing the nuts, wiggle or pry the manifold off the studs away from the cyl head. How to replace gas-tractor manifold gaskets STEP 3: Clean both surfaces the gasket seals against, the head and the manifold ports. Wear eye and ear protection when cleaning and especially if using power tools. Inspect the manifold ends for any raised areas that could be burnt gasket material disguising itself as rusted metal. Remove the old gasket residue until the flat steel surface is clean. STEP 4: Inspect the head surface for an uneven surface where the gasket seals, especially on the end exhaust ports. A slight uneven surface is serviceable, but any area where the steel is eroded or rusted away more than 1/32-inch will lead to premature failure of the gasket unless the surface is milled or planed flat by a machine shop. Inspect the manifold port sealing areas, as well. Use a straight-edge to check that all ports are even and flat where they seal against the gasket. If any area is eroded or rusted away, the manifold should be machined flat again. However, no more than .2-inch should be removed from the manifold or the carburetor linkage may bind when the carb is attached to the manifold. Most manifolds with blown-out gaskets need to be resurfaced for best life expectancy of the new gaskets. 10 OLD ALLIS NEWS