New Step Gap turbine shaft seal (also known as Staggered Gap or Stepped Gap Seal) for Holset HX35 HX35W H1C HX30 HX40 HX50 HE351 turbochargers. Replaces oem part number 56754. 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. Eliminates smoking and oil consumption. As a stock seal wears the gap grows bigger, but Step Gap seals retain a gapless seal even after years of heavy use. Greatly reduces the power robbing deposits and residue inside 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.