Pitman arm for Zone 4” Suspension System A frequent question I receive about this suspension system is if a pitman arm is necessary.  The simple answer is no, if it needed it, we would include it, but here’s a shot at the explanation why. A major part of the steering geometry is the working relationship between the track bar and the drag link.  Through suspension travel these both travel in an arc based on their fixed pivot locations. The length of these components, as well as the installed angles will determine the radius of the arc and what portion of the arc