The Physics of Lateral Shift and How to Stop It

The biggest enemy of a motorhome driver is lateral movement. In a perfect world, a vehicle only moves in two directions: forward and up and down to absorb bumps. However, in the real world of crosswinds and rutted highways, a large vehicle is subjected to intense side to side forces. This lateral shift is what causes a rig to feel unstable and "darty" at high speeds. To achieve a truly stable ride, we must look at how to anchor the vehicle's body to its axles more effectively.

The SuperSteer SS450 Rear Trac Bar is the most effective mechanical solution for lateral axle shift. On a standard leaf spring suspension, there is a small amount of side to side flex inherent in the springs. When you are driving a tall, heavy motorhome, this flex is amplified. The trac bar creates a solid bridge between the axle and the frame. It essentially forces the axle to move in perfect sync with the rest of the vehicle. This eliminates the "tail wag" that is so common in Class A coaches. Once the rear axle is anchored, the driver no longer has to over-correct for every gust of wind or passing truck.

Up front, the steering system needs the same level of rigidity. The SuperSteer SS100 Bell Crank addresses the pivot point of the steering linkage. While the rear trac bar stops the axle from sliding, the bell crank ensures that the front wheels stay exactly where the driver points them. By replacing the stock plastic bushings with high precision tapered roller bearings, the SS100 removes the "dead spot" in the steering. This is the area where you can turn the wheel slightly without any reaction from the vehicle. Removing this play is essential for maintaining a straight path on the highway with minimal effort.

To further refine the steering response, the SuperSteer SS3032 Bell Crank Arm provides the necessary strength to transfer steering forces without flexing. In heavy duty applications, even high quality steering boxes can be let down by weak linkage arms. The SS3032 is a reinforced component that ensures the mechanical leverage of your steering system is maximized. This results in a firm, confident feel that tells the driver exactly what is happening at the tire level. It is this combination of a tight pivot and a rigid arm that creates a steering system capable of handling the demands of a twenty thousand pound vehicle.

Understanding the relationship between the front and rear of the chassis is key to a successful suspension tune. You cannot fix a wandering front end if the rear axle is sliding side to side. Conversely, an anchored rear axle will still feel vague if the front steering linkage is full of play. By addressing both ends of the vehicle with specialized hardware, you create a cohesive platform that responds predictably to road conditions. This level of mechanical harmony is what makes long distance travel a joy instead of a chore.

You can find the technical specifications and application guides for the entire SuperSteer catalog at Shockwarehouse.