Abstract: A sprocket retention/chain guide member for use in the timing drive mechanism for an internal combustion engine where a timing chain acts to rotate the engine camshaft from the crankshaft and time the opening and closing of the inlet and exhaust valves for the engine cylinders based on reciprocation of the pistons. The retention/guide member is adapted to be mounted on the front of the engine block and has oppositely disposed arcuate grooves loosely receiving the crankshaft and camshaft sprockets and guide channels on each side of the member acting as snubbers for the chain. The member, chain and sprockets form a subassembly for shipping and ease of assembly on the block with the sprockets being received on the crankshaft and camshaft. Also, a chain tensioner may form a portion of one guide channel.