Abstract: A sub-frame assembly for use with a vehicle having wheels such as a trailer is provided. The sub-frame assembly comprises two or more frame members, one or more cross members, and two or more stub torsion axle assemblies. Each of the stub torsion axle assemblies have a torsion arm, a spindle extending from the torsion arm for mounting one of the wheels, and a distal end extending from the stub torsion axle assembly for mounting to the frame assembly. The frame assembly may further comprise one or more shim plates for reception between the cross member and the distal end of the stub torsion axle assembly for allowing adjustment of the toe angle of the wheel assembly. In addition, the stub torsion axle assembly may be rotatably mounted to the cross member whereby the camber angle of the wheel assembly may be adjusted.