Slipper clutches and non-slipper clutches use different pressure plates.
If you look at the other side of the pressure plate, you'll see that the standard (non-slipper) plate is notched, but a slipper plate is not.
This is standard clutch plate:
this is a slipper clutch plate:

Last edited by antonye : 15-Oct-2012 at 14:23.