Co-axial sway bar for a suspension system

A suspension system for a vehicle having a frame, comprising:

• a first interface member;
• a second interface member, wherein the first interface member and the second interface member are positioned along a common central axis;
• a connector coupled to the first interface member, the connector comprising:
• an outer support member configured to be coupled to the frame of a heavy duty truck or trailer;
• and
• an inner race coupled to an outer surface of the first interface member and positioned at least partially within the outer support member;
• a flange extending radially outward from the outer surface of the first interface member;
• a thrust bearing disposed between the flange and the inner race, wherein the flange is configured to engage the thrust bearing and limit axial movement of the first interface member;
• a first body member coupled to the first interface member and configured to rotate about the common central axis;
• a second body member coupled to the second interface member and configured to rotate about the common central axis;
• and
• a torsion spring coupled to the first interface member with a first splined connection and coupled to the second interface member with a second splined connection different than the first splined connection, wherein the first splined connection includes a male and a female spline having a first diameter and the second splined connection includes a male and a female spline having a second diameter that is greater than the first diameter, wherein the torsion spring is disposed along the common central axis.