Can you change the clutch on a 911?
The clutch is quite sensitive to changes in the cable length, and once you get into the ballpark, only minute changes in the cable are necessary to dial in the clutch to your preferences. For 911s with the late-model 915 transmission, there is a specific factory adjustment procedure that seems to work quite well.
When did Porsche change the clutch helper spring?
In 1977, Porsche installed a helper spring mechanism (See Pelican Technical Article: Replacing Your Clutch Helper Spring) to give a better feel to the clutch pedal. This mechanism is a bit more complicated to adjust, but involves less guess-work.
What should the total throw of the clutch cable be?
The total throw of the clutch cable should be 25mm (.5mm as measured at the transmission). If this distance is not within the specified range, then adjust the rubber stop that is attached to the wooden floorboard behind the clutch pedal arm in the passenger compartment.
The clutch is quite sensitive to changes in the cable length, and once you get into the ballpark, only minute changes in the cable are necessary to dial in the clutch to your preferences. For 911s with the late-model 915 transmission, there is a specific factory adjustment procedure that seems to work quite well.
How big should the release Fork be on a Porsche 911?
When the clutch pedal is pressed completely to the floor, the travel on the throw out release fork should be about 0.6 in (15mm). Of course, this distance is highly dependent upon the condition of your clutch components.
The total throw of the clutch cable should be 25mm (.5mm as measured at the transmission). If this distance is not within the specified range, then adjust the rubber stop that is attached to the wooden floorboard behind the clutch pedal arm in the passenger compartment.
In 1977, Porsche installed a helper spring mechanism (See Pelican Technical Article: Replacing Your Clutch Helper Spring) to give a better feel to the clutch pedal. This mechanism is a bit more complicated to adjust, but involves less guess-work.