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 Share on Facebook (Opens in new window) Facebook Share on X (Opens in new window) X Share on Reddit (Opens in new window) Reddit Share on Pinterest (Opens in new window) Pinterest Share on LinkedIn (Opens in new window) LinkedIn