Linking Outside the Box
There are two common configurations for solid-axle suspensions located by control arms: those with triangulated links to locate the axle side to side, and those with a track bar (Panhard bar) to locate the axle side to side. If you are using a steering box with a linked front suspension then 99 percent of the time you’ll have a track bar setup. But the triangulated suspension offers advantages such as smooth vertical motion as the axle cycles through its travel, whereas a track bar suspension pushes the axle side to side on extension and compression.
If you run a steering box with the common crossover steering system on a triangulated link suspension, you’ll get bumpsteer as the arc of the suspension does not match the arc of the drag link. This is why most front triangulated link suspensions on Jeeps and buggies for off-road use end up with a full hydraulic steering system with no drag link or steering box. Full hydro is great, but the safety of a mechanical system is hard to beat as a fail-safe if you have to limp off the trail or plan on driving on the street. How do you get triangulated four-link suspension performance with steering box reliability? The secret is for the steering linkage to mimic the travel arc of the suspension, and this can be accomplished with a variety of steering styles.
The secret is for the steering linkage to mimic the travel of the suspension
How you achieve that goal is open to interpretation. Some builders leave the steering box in the stock location, while others put the box elsewhere on the frame and use multiple drag links and bell cranks to steer the axle. Though more complicated than a simple box and drag link design, similar steering systems were used in early Jeeps as well as mid-’80s solid-axle desert race trucks. Push-pull steering like this is not inherently flawed, but it does get a bad reputation because the factory drag links on Toyotas and GM pickups were so short and multiple drag links allow multiple tie-rod ends to loosen and get sloppy. After you lifted these vehicles the angle of the drag link became so severe at ride height that the steering could bind and fail when the suspension articulated. Don’t throw away your steering box and convert to full hydraulic just yet though, because there are plenty of creative options for retaining mechanical steering that are strong and will accommodate massive articulation with little to no bumpsteer.