Vehicle With Front-Wheel-Assist System

A heavy-duty vehicle may include a vehicle frame, a plurality of rear-wheel assemblies, and a plurality of front-wheel assemblies. The wheel assemblies are mounted to the vehicle frame. Each of the front-wheel assemblies may include a rim, a spindle, a brake assembly, a motor, and a transmission assembly. The spindle may be at least partially disposed within the rim. The brake assembly may be disposed within the rim and may extend around the spindle. The motor may be disposed within the cavity in the spindle. At least a portion of the motor is disposed between first and second axial ends of the rim. The transmission assembly may be disposed within the rim. The transmission assembly may transmit rotary motion of the motor to the rim to rotate the rim relative to the spindle.