All parts are manufactured to meet or exceed the original part it is replacing. Bronco differential bearing & seal kits include all bearing and seals necessary to do a differential rebuild and feature: • High-speed bearings bearings that meet ABEC industry precision standards. • Sealed bearings use double or triple lip seals with stainless steel garter springs to better keep the grease in and the water and dirt out. • Premium grease contains rust and oxidation inhibitors.