87 911 turbo 4 speed trans clutch problem

I have got 72k on my 911 turbo. I have noticed a clinking noise every time tap the gas pedal. someone told me the rubber piece located on the back of the pressure plate is worn out. does anyone know anything about this issue?

I have a similar clunking when I tap the throttle on my turbo as well as other turbo's I have driven. My theory is the clunking is coming from the pop-off valve located on the pressurized side (post turbo)of the intake track. The pop-off valve allows pressurized intake air to be dumped back over to the unpressurized side of the intake track (pre-turbo) when the throttle is closed to prevent the turbo from instantly spinning down due to a pressure build up against a closed throttle plate. If the noise does not change with clutch engagement or disengagement I would rule out the clutch, mine has a brand new clutch and the noise did not change. Keep us turbo guy's posted if you get to the bottom of this mystery, Thanks T. Roy