To this day, a chassis development is used that was introduced at Mercedes-Benz over three decades ago as a spatial steering axle.
The trick: instead of two superimposed wishbones, the wheel of the spatial steering axle is guided by five individual wishbones. Technicians describe the result as “guiding precision”. This design, devised by designer Manfred von der Ohe, achieves the ideal situation: the individually suspended wheel rolls exactly vertically on the road surface in every driving situation. This could not be achieved with the designs commonly used until then. The revolutionary spatial steering axle only allows the compression and rebound movement and keeps the wheel in the optimum position. The result is largely neutral handling, which noticeably increases driving safety.
The spatial steering axle follows an ideal formulated by the ingenious racing car designer Colin Chapman: “The best wheel guidance is that which does not steer at all.” It was a long road before this theory was transferred for use in a production car. It led via the Mercedes C111 prototype from 1970, which already had a similar rear axle design to the 190 later on. However, in contrast to the hard-tuned sporty two-seater with its heavy borrowing from racing car construction, the space-steering axle in the everyday car also had to meet the demands for comfort. Instead of the uniball joints used in the C111, the five control arms in the production model were guided in softer rubber bearings.
The revolutionary rear axle design should actually have been ready for the S-Class of the W126 model series presented in 1979. But there was not enough time, and the space-steering axle only celebrated its premiere in the completely newly developed 190 at the end of 1982.
This replaced the diagonal swing axle in Mercedes passenger cars. In addition to the improved driving characteristics, the new rear axle had another advantage: compared to the swing axle, it was a quarter lighter. The four control arms are only loaded with push and pull. No torsional forces act on them, so they can be manufactured with less effort.
Mercedes-Benz had the principle of the spatial steering axle protected as a patent. However, this expired after 20 years. This means that other manufacturers can now also benefit from Ohes’ design. We at RPR-Motors have therefore found a solution to integrate the spatial steering axle into our restomods.