Differential Cover, Rear - Sterling 12-10.25/10.5 w/Single Rear Wheel - Ford 1989-2016 F250/F350, 2017-2019 F250
BD's design deflects the oil back onto the ring gear and into the pinion gear for cooler longer life. Other differential covers are large and bulky resulting in lubricating oil being flung off the ring gear causing addition heat and/or wear.
