The pinion seal, also called a pinion shaft, is designed to keep oil in and any water, dirt or debris out. As long as the pinion seal is in place and performing well, the differential will stay in good shape and operate as it is supposed to.
Sold individually.
Fits all 2002-2021 Subaru WRX and 2004-2022 WRX STI rear differentials. Fits most other late-model Subarus, too.
