The rear axle of the A-Class is a new development whose description alone is enough to arouse the curiosity. The “spherical parabolic-spring rear axle” is the result of sev-eral years of complex development and testing work by Mercedes engineers and makes a key contribution to the exceptional driving dynamics and impressive ride comfort of the new A-Class.

The centrepiece of this intelligent construction is the forwards-arched axle housing, which takes the place of conventional control arms and serves to secure the wheels. The axle housing is fixed to the car body by separately arranged springs and shock absorbers, the anti-roll bar and a centrally located elastomer central bearing. A special linkage named after the brilliant British inventor James Watt is responsible for wheel location and support against lateral force. The two struts of the Watt linkage are attached to the rear section of the axle housing and connected by a rotating coupling in the centre to the car body.

The axle housing consists of two sheet steel shells, whilst the Watt struts are manu-factured using internal high-pressure forming processes and thus display outstanding rigidity. The axle components are protected from stone chipping by additional plastic coverings, which also offer aerodynamic benefits. The Watt coupling is a robust forged part.