The present invention comprises a trailer main frame with a first rocker assembly and a second rocker assembly pivotally attached to the trailer main frame wherein the rocker assemblies are attached to leveling means such as but not limited to hydraulic and or air system between the trailer main frame and the rocker assemblies.

A utility vehicle includes a plurality of ground-engaging members, a frame, a powertrain assembly, a front suspension assembly, and a rear suspension assembly. A cargo bed may be supported by the frame at the rear of the vehicle. The vehicle also includes an operator seat and at least one passenger seat positioned within an operator area. In one embodiment, the vehicle includes doors to enclose the operator area.

A utility vehicle includes a plurality of ground-engaging members, a frame, a powertrain assembly, a front suspension assembly, and a rear suspension assembly. A cargo bed may be supported by the frame at the rear of the vehicle. The vehicle also includes an operator seat and at least one passenger seat positioned within an operator area. In one embodiment, the vehicle includes doors to enclose the operator area.

A spring assembly for a non-rail wheeled or tracked vehicle is provided. The spring assembly includes a piston, and a sleeve with variable thickness. The sleeve is made from an unreinforced synthetic elastomeric material and being free of reinforcing fibers. The sleeve is coupled with a plurality of end components and defines a deformable pressure vessel, and the deformable pressure vessel supplies a support force.

A spring assembly for a non-rail wheeled or tracked vehicle is provided. The spring assembly includes a piston, and a sleeve with variable thickness. The sleeve is made from an unreinforced synthetic elastomeric material and being free of reinforcing fibers. The sleeve is coupled with a plurality of end components and defines a deformable pressure vessel, and the deformable pressure vessel supplies a support force.

A method for forming an air spring for a vehicle including a frame coupled to the air spring includes heating an elastomeric base material to a melting point of the elastomeric base material, thereby forming a melted elastomeric base material, forming a sleeve from the melted elastomeric base material, the sleeve being substantially free of textile reinforcing fibers, and engaging the sleeve with end components, the sleeve and the end components defining a deformable pressure vessel, where the deformable pressure vessel supplies a supporting force.

A method for forming an air spring for a vehicle including a frame coupled to the air spring includes heating an elastomeric base material to a melting point of the elastomeric base material, thereby forming a melted elastomeric base material, forming a sleeve from the melted elastomeric base material, the sleeve being substantially free of textile reinforcing fibers, and engaging the sleeve with end components, the sleeve and the end components defining a deformable pressure vessel, where the deformable pressure vessel supplies a supporting force.

A method for forming an air spring for a vehicle including a frame coupled to the air spring includes heating an elastomeric base material to a melting point of the elastomeric base material, thereby forming a melted elastomeric base material, forming a sleeve from the melted elastomeric base material, the sleeve being substantially free of textile reinforcing fibers, and engaging the sleeve with end components, the sleeve and the end components defining a deformable pressure vessel, where the deformable pressure vessel supplies a supporting force.

A method for forming an air spring for a vehicle including a frame coupled to the air spring includes heating an elastomeric base material to a melting point of the elastomeric base material, thereby forming a melted elastomeric base material, forming a sleeve from the melted elastomeric base material, the sleeve being substantially free of textile reinforcing fibers, and engaging the sleeve with end components, the sleeve and the end components defining a deformable pressure vessel, where the deformable pressure vessel supplies a supporting force.

A utility vehicle includes a plurality of ground-engaging members, a frame, a powertrain assembly, a front suspension assembly, and a rear suspension assembly. A cargo bed may be supported by the frame at the rear of the vehicle. The vehicle also includes an operator seat and at least one passenger seat positioned within an operator area. In one embodiment, the vehicle includes doors to enclose the operator area.