Panhard rod
| Industry | Automotive |
|---|---|
| Founded | 1891 |
| Founder | René Panhard, Émile Levassor |
| Headquarters | France |
A Panhard rod—also known as a Panhard bar, track bar, or track rod—is a type of suspension link that controls the lateral positioning of an axle. This component was originally developed by the French automobile manufacturer Panhard in the early 1900s and continues to be extensively utilized today.
Overview
The function of an automobile suspension system is to allow wheels to move vertically relative to the vehicle body while restricting movement in both longitudinal and lateral directions. The Panhard rod serves as a straightforward mechanism aimed at preventing side-to-side axle displacement. It is composed of a rigid bar oriented laterally within the axle plane, connecting one side of the axle to the opposite side of the chassis. The rod is mounted using pivot points that permit only vertical rotation, thereby confining axle motion to the vertical axis. Because it does not provide longitudinal axle location, it is commonly used alongside trailing arms to maintain stability along the vehicle’s length.
Typically, Panhard rods are paired with coil spring suspensions, since leaf spring setups generally offer adequate lateral stiffness on their own. For example, Ford incorporated a similar rear axle stabilizer (known as a fifth shock) on certain Explorer models and light trucks equipped with rear leaf springs. Additionally, Jaguar utilized a Panhard rod for rear axle positioning on its cantilever leaf-sprung Mark 2 model.
Advantages and disadvantages
The primary benefit of the Panhard rod lies in its mechanical simplicity. However, its main limitation is that the vehicle body moves along an arc relative to the axle, with the radius determined by the length of the rod. When this rod is short, it permits significant lateral displacement at extreme suspension travel points, which makes it less ideal for compact vehicles.
Some exceptions exist, such as the Mitsubishi Pajero Mini and Suzuki Jimny, which are small off-road models where minor lateral movement between axle and chassis is less problematic. A related mechanism designed to minimize sideways axle movement more effectively is the Watt's linkage.
Applications
In certain vehicles featuring live-axle suspensions where design limitations prevent using a Watt's linkage, a Panhard rod is employed instead—sometimes even in front suspension setups. A notable example is the Mercedes-Benz G-Class, which underwent a redesign in 2018 to incorporate a Panhard rod on its rear axle, thereby improving handling performance on paved roads.