Dodge Dart Pitman Arm
If I am reading this right it sounds like the ball joint that is at the end of the pitman arm is shot. The shaft should not spin by it self, it pivots like any other ball joint but it should not just turn when tighten the castle bolt. A new pitman arm is about $72 I just replaced mine 2 days ago. If and when you do replace it make sure you get a pitman arm puller or you will never get the dam thing off. I swear itÂ’s the hardest thing to get off a car. As a side note just note the position of the pitman arm before you remove it so you can line up the new one when you put it on. Its no hard to do because the inside of the pitman arm is clocked so you cant really put it on wrong as long as you know which way it was facing when you took it off. If I under stood your post this should help you somewhat.