Originally Posted by
dweenk
When you get your tool, be careful not to cross-thread the extractor while screwing it in. If that happens, you have created another problem.
+1. And do not buy a cheap crank extractor. Cheap could mean sloppy threads and tolerances. You're carefully screwing a steel tool into aluminum threads. If the cheap tool does not fit REAL nicely you can easily strip those aluminum threads and you then need to cut the crank arm off.
And clean the tool well and clean the threads in each crank arm well. I use an old tooth brush and some mineral spirts. Nice and clean then get the tool started very carefully as stated above.