A piston clutch system comprising: a housing; a piston configured to slide within the housing; a shaft; and a clutch pack; the piston comprising: a shaft side with a first circumferential groove, said first circumferential groove bounded by a continuous circumferential seal plateau, said seal plateau extending axially outward from said first circumferential groove, wherein a planar outboard surface extends radially outboard from said seal plateau; a clutch side having two grooves (98, 104) alternating with two lands (100, 102); an inner circumferential surface having a seal groove formed therein; and an outer circumferential surface with a having a seal groove formed therein, wherein the sides and surfaces form a ring shape; wherein the shaft extends through the inner circumferential surface of said piston and the clutch pack is in direct contact with the clutch side of said piston; characterized in that said outer circumferential surface has a first portion and a second portion, the second portion having a ridge with a diameter larger than a diameter of the first portion, said second portion having a seal groove formed therein configured to accommodate a fluid seal; wherein the second portion is configured to fit within the housing; wherein the first circumferential groove transitions from the inner circumferential surface to the seal plateau with a radius and has a constant outer diameter and a constant axial depth into the piston; wherein at an outer diameter of the seal plateau, the seal plateau transitions into the planar outboard surface with a radius; and wherein the seal plateau is the only portion on the shaft side of the piston that is configured to come into contact with the housing. a housing; a piston configured to slide within the housing; a shaft; and a clutch pack; the piston comprising: a shaft side with a first circumferential groove, said first circumferential groove bounded by a continuous circumferential seal plateau, said seal plateau extending axially outward from said first circumferential groove, wherein a planar outboard surface extends radially outboard from said seal plateau; a clutch side having two grooves (98, 104) alternating with two lands (100, 102); an inner circumferential surface having a seal groove formed therein; and an outer circumferential surface with a having a seal groove formed therein, wherein the sides and surfaces form a ring shape; wherein the shaft extends through the inner circumferential surface of said piston and the clutch pack is in direct contact with the clutch side of said piston; a shaft side with a first circumferential groove, said first circumferential groove bounded by a continuous circumferential seal plateau, said seal plateau extending axially outward from said first circumferential groove, wherein a planar outboard surface extends radially outboard from said seal plateau; a clutch side having two grooves (98, 104) alternating with two lands (100, 102); an inner circumferential surface having a seal groove formed therein; and an outer circumferential surface with a having a seal groove formed therein, wherein the sides and surfaces form a ring shape; wherein the shaft extends through the inner circumferential surface of said piston and the clutch pack is in direct contact with the clutch side of said piston; said outer circumferential surface has a first portion and a second portion, the second portion having a ridge with a diameter larger than a diameter of the first portion, said second portion having a seal groove formed therein configured to accommodate a fluid seal; wherein the second portion is configured to fit within the housing; wherein the first circumferential groove transitions from the inner circumferential surface to the seal plateau with a radius and has a constant outer diameter and a constant axial depth into the piston; wherein at an outer diameter of the seal plateau, the seal plateau transitions into the planar outboard surface with a radius; and wherein the seal plateau is the only portion on the shaft side of the piston that is configured to come into contact with the housing.