Abstract: For a motor vehicle suspension of the type including dual leaf spring assemblies and a connecting rocker arm, a pair of elongated generally coextensive downwardly arched leaf springs in laminar coactive load-supporting relation include a front end attachment eye on the upper of the springs and a fail-safe terminal portion on the lower of the springs substantially enveloping the eye. The rear end portions of the springs have nested upwardly arched load supporting portions for engagement with the rocker arm. In non-loaded and normally loaded conditions of the associated vehicle the leaf springs provide constant rate spring action, and when excessive suspension random loads must be supported supplementary compression spring means carried by the leaf springs engage the vehicle frame with progressively increasing spring rate and avoid overstressing the leaf springs.