Abstract: A lift axle suspension adapted to be mounted to a vehicle frame for selectively supporting a vehicle frame on an axle with ground engaging wheels includes a pair of trailing arm assemblies each of which includes a hanger bracket adapted to be mounted to the vehicle frame, a trailing arm pivotally mounted to the hanger bracket for pivotal movement relative to the frame about a pivot axis, a spring operably connecting the trailing arm to the vehicle frame for resisting the pivotal movement of the trailing arm about the pivotal axis toward the frame, an inflatable lift bag operably connecting the trailing arm to the hanger bracket and for selectively raising the trailing arm relative to the frame when the lift bag is inflated and an axle rigidly mounted to the trailing arm. The iift bag is positioned inboard of the hanger bracket and the trailing arm. The hanger bracket is adapted to be mounted to the outboard side of the frame rail.