May I suggest: please, get it off that beautiful hardwood flooring, Have a helper use /stand on the 24" pipewrench at the spline tool. Place a min. 3' pipe over the wrench and pull/ jerk sharply in the same direction as person standing. The wrenches in the op's pic are on the left and look in the proper position for pulling on aforementioned pipe if the (open end of) wrench was rotated somewhat higher first. Yes, imp has l/h threads. It feels very "springy" when you twist, because as mentioned above , the long shaft acts like a torsion bar.