GM-51618 is a double-ended tool that installs the axle shaft roller bearing into the axle tube at the outer end on both 200 mm and 220 mm ring gear rear axles, and installs the side bearing onto the differential case on the 220 mm ring gear rear axle. The roller bearing is positioned to a specific depth in the axle tube, and the GM-51618 ensures the bearing is positioned correctly. GM-51618 is used with the GM-8092 Driver Handle to install both bearings. Incorrect installation will result in shortened service life for the bearing.