One of the easiest ways to prevent leaks is to use a new gasket whenever parts that require them are split. One such part is the differential cover, so PPE offers this Rear Diff Cover Gasket for GM and Dodge 2500/3500 series trucks (with American Axle). Made from MicroPore CMP-4000 material, this gasket is cheap insurance against leaks that not only reduce the level of fluid in your differential; they make a mess of your driveway, too.