New Stepped Gap turbine shaft seal (also known as Staggered Gap or Step Gap Seal) for Garrett TP38 and GTP38 turbochargers. The TP38 and GTP38 turbos were used extensively on 7.3 L Ford Powerstroke Diesels. This piston ring type seal is installed on the turbine (hot) side of your turbine shaft. Stepped gap seals are designed reduce oil blow by of the Turbine (rear) seal and are made to withstand extreme temperatures created by your turbocharger. The design having a stepped end ensures a gapless seal as the steps overlap reducing possible blow by past the seal and into the turbine housing. As a stock seal wears the gap grows bigger, but Stepped Gap seals retain a gapless seal even after years of heavy use. Greatly reduces the power robbing deposits and residue in your turbine housing and on your turbine wheel caused by oil leaking past the turbine seal. Provides the ultimate seal. Free shipping within the USA. Worldwide shipping is $6.75. Paypal accepted.