16 and the piston housing 100 the first differential case portion 90 can define an annular pocket 110 fig4 and a plurality of blind bores 114 fig3 the annular pocket 110 can be defined by an outer circumferential wall 120 an inner circumferential wall 122 and an end wall 124 the end wall 124 can be integral to the common wall 102 the first differential case 90 can further include an annular lip 128 formed in part by the inner circumferential wall 122 the blind bores 114 can be receive planet gear shafts 130 that support the planet gears 50 of the planetary gear assembly 16 a first o ring 134 can disposed between the piston 82 and the outer circumferential wall 120 of the annular pocket 110 in one example the piston 82 can define an outer annular recess 136 the first o ring 134 can nest in the outer annular recess 136 a second o ring 140 can be disposed between the piston 82 and the inner circumferential wall 122 of the annular pocket 110 in one example the piston 82 can define an inner annular recess 142 the second o ring 140 can nest in the inner annular recess 142 during operation of the clutch assembly 32 the piston 82 can be.