Melling recommends new camshaft timing gear bolts with every engine rebuild. Old bolts are subject to metal failure, bolt stretching, and worn threads. Bolts also tend to be lost or damaged during the rebuilding process. There is also a danger of metal cracking when the camshaft timing gear bolt is removed. Melling camshaft timing gear bolts are manufactured to high quality and material standards and meet or exceeds OE performance requirements.