Home » Training » Trailer Glossary » Converter Dolly Converter Dolly A Converter Dolly is an auxiliary axle assembly equipped with a fifth wheel that connects two semitrailers. They are available in both single axle and tandem axle configurations. Key Components Drawbar EyeFifth WheelLegFrameAxle(s)WheelsTiresAir ComponentsElectrical Components Click to share on Facebook (Opens in new window) Facebook Click to share on X (Opens in new window) X Click to share on Reddit (Opens in new window) Reddit Click to share on Pinterest (Opens in new window) Pinterest Click to share on LinkedIn (Opens in new window) LinkedIn