Abstract: An hydraulic clutch comprises coaxial input and output shafts with driving and driven discs respectively mounted on the shafts. The mounting of the driven discs on the output shaft includes a one piece member having a cup with an annular wall that surrounds the input shaft and the driving discs. The one piece member also includes the output shaft. An hydraulic piston is used to engage the clutch discs; and pins, around which return springs are mounted, limit the throw of the piston. The arrangement tends to minimize turbulence, heat build-up, and power losses when the clutch is in the disengaged condition.