The Rein Upper Timing Chain Cover EA888 is an essential component that includes the required seals and bolts. It is a must to replace when performing a timing chain job. This cover plays a critical role in sealing the upper portion of the timing chain assembly, protecting it from contaminants and ensuring proper lubrication. By replacing the upper timing chain cover during a timing chain job, you can prevent potential leaks and maintain the integrity of your engine's timing system.