The Spicer Drivetrain Components 50531 Pinion Seal is available for those of you who are performing a rebuild, or general maintenance on your differential. When performing service toy our differential, it is imperative that you use quality components that meet or exceed the demands of OEM build quality to provide you with years of performance and reliability. With that said, you can trust Spicer Drivetrain Components to deliver both quality, and dependability.