An elastomeric spring suspension is described for supporting a longitudinally extending vehicle frame rail above first and second axles forming a tandem axle configuration. The suspension includes a frame hanger assembly mounted to the vehicle frame rail. The frame hanger assembly has two full spring modules, each of which includes two shear springs, a progressive spring rate load cushion having a pyramidal shape with a flattened top surface and a spring mount for mounting the springs. A saddle assembly is connected to the spring mount, and an equalizing beam is connected to the saddle assembly and further connected to the axles. The spring rate for the suspension increases almost linearly as a function of sprung load, resembling a pneumatic suspension. Accordingly, the suspension exhibits excellent ride quality, without sacrificing roll stability.