A crucial problem in designing a servoactuated manual transmission is posed by the clutch torque variations which depend on operating conditions with equal clutch pedal position and clutch slip. An experimental study of the phenomena that determine torque variations can be particularly useful in coping with this problem. To this end, the authors developed a powertrain test bench. The bench makes it possible to measure the main magnitudes (disc temperature, clutch slip, clamp load and clutch disc displacement) which can influence transmitted torque. Test bench layout is described. Some experimental results are presented and discussed, with particular attention to the problems connected with clutch controller design.