A tractor includes a frame including an axle, the axle including an axle shaft and a beam member. A cab is mounted to the frame, the cab including controls for controlling the tractor. A ground-engaging mechanism coupled to the axle, the second ground-engaging mechanism including a track assembly. The track assembly includes an undercarriage assembly, a carrier housing, a ring gear, and a track, where the carrier housing includes a pivot arm for pivoting coupling to the undercarriage assembly. The ring gear defines an outer diameter, and the axle shaft and beam member are adjustably coupled to the carrier housing at a location inside the outer diameter.