GM-48853 aligns the front cover for installation on 4.8L, 5.3L, 6.0L, 6.2L, and 7.0L V8 engines. A key is being added to the crank hub to retain the balancer starting in the 2008I model year. If the cover is not properly centered on the crankshaft, the front seal will fail, resulting in leaks. Due to the keyway, which is combined with the larger cover required by engines with cam phasers, the previously Essential GM-41476 and GM-47813 will no longer fit these engines. GM-48853 centers the front cover while fitting over the crank key, allowing the cover to be installed in the correct position, centered around the crankshaft. GM-48853 allows for cover installation without requiring the removal of the seal included in the new cover, and adapters are included to enable GM-48853 to back-service to 1998.