GM-50441 installs the hub oil seal and retainer into the rear axle hub. Once the inner bearing cup and cone are installed into the hub, the seal and retainer are piloted into the hub. GM-50441 is installed over the seal and retainer and used with a hammer or mallet to install the seal into the correct position. Unapproved installation methods may not place the seal into the correct position, and may result in less than designed seal life. GM-50441 supersedes GM-43413.