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 they move through.
In a perfect world, we would make these components travel in the exact same angle and radius relationship. Due to clearance problems and really the design of the steering system, these are not perfect from the factory. When lifting these vehicles, it is best to try to keep the moving relationship between them as close as possible.
We list in our instructions to drill a new hole in the factory axle mount to re-center the axle by mounting the track bar to the new hole. This will get it close. If you want it perfectly centered, we offer the adjustable track bar upgrade and you can re-use the factory hole.
Since our lift does not relocate the track bar vertically in any manner, there is no reason to include a pitman arm with our suspension system. If we did so, the angle of the drag link would be reduced and now be more mismatched to the angle of the track bar. As the axle is travels in an arc controlled by the track bar, the steering will be pushed or pulled to match the travel of the axle. This is what most commonly people refer to as bump steer.
Please feel free to post your comments or further questions on this blog.