1944902 Inner Valve Spring Fits Caterpillar Industrial Construction ModelOne New Aftermarket Replacement Inner Valve Spring Fits Caterpillar (Fits CAT) 3500 Series Engines This inner valve spring is a direct replacement Fits Caterpillar (Fits CAT) 3500 Series diesel engines, seating within the cylinder head valve assembly alongside the outer valve spring to maintain proper valve timing and sealing under high cycle, heavy duty operating conditions. The Fits Caterpillar 3500 Series is used across industrial, construction,