And it just threads into the base, does not pass through. I had even contacted Tracker's Tech. Support folks for advice on removing the stubborn king pin, thanks for the replies Max, amazing that you can get live human tech support on a 33 year old product! So soaked it in Kroil penetrating oil, heated the area with a propane torch and left it to sit for a few days. Managed to get it removed first trying a stud remover and after that failed, clamping the threaded stud in a vice and using a large Crescent wrench on the baseplate and JUST BARELY was able to get that sucker broken loose (without snapping it off). Since the old threads in the base plate looked pretty cruddy, decided to modify it to take an aircraft bolt.   (21/70)