double check to see if the threads in the clutch are not stripped. The tool is steel and the clutch is aluminum. it is common for the clutch to strip out. the end of the tool should have about 1/4" tip that is not threaded. We have ground those down in the past to make it work, but keep in mind there is probably not many threads left in the clutch.
you could always use a bolt of the same size to open the clutch or install a thread repair kit. sorry, cant think of what they are called. Any auto parts store should carry them.