I stripped one that I had on a ricky stator flywheel, it was a cheapo, I screwed it in straight but it was hard cranking and only got about 4 threads in. I replaced it with the more expensive one from Dennis Kirk I think it was like $15 and it might have been a motion pro. I contacted RS and they said you should put grease on it before you screw it into their wheel, after I got the new puller and greased it, it went right in by hand.