Originally Posted by Crankycrank

First of all, the advice to not try to pull the crank without the puller screwed all the way in is accurate. If you're positive that the puller is the correct thread pitch and made of quality steel you can use it as a thread chaser. Kerosene is the best thread lube to use to tap aluminum but any type of oil would be OK. Thread the puller in a 1/4 turn at a time back it out a little and repeat until it's bottomed out. Of course if you have to use gorilla strength then you'll need a proper thread chaser but try using the tool first.

Originally Posted by mororian

Well, it turns out I was able to (carefully) thread it all the way in with the help of a wrench and WD-40, and the arm popped right off, so problem solved!