14 mounted on the front and rear frames 13a and 13b and its direction of movement can be changed by bending the front frame 13a relative to the rear frame 13b by the action of the steering cylinders 17 mounted therebetween as shown in fig4 during excavating and loading operations the vehicle is once stopped at the excavation site and the rotatable vehicle body 1 is permitted to gyrate by the gyrating motor 20 while excavation and loading operations are effected by the implement 3 therefore movement of the vehicle body back and forth for excavation and loading operations needed in the case of the conventional loader mounted vehicle can be eliminated and so the operational efficiency can be improved remarkably and remarkable wear down or consumption of wheels 14 can be avoided further fig3 shows an embodiment in which the axial cylinder 15 is formed on one end of the rear frame 13b so that the front frame 13a can be rotated about the axial cylinder 15 however the arrangement may be made such that the axial cylinder 15 is formed on one end of the front frame 13a so that the rear frame 13b can be rotated about the axial cylinder 15 fig5 shows another embodiment of the present invention in which the rotatable or gyrating vehicle body 1 and the front frame 13a are rotatably mounted on the rear frame 13b and.