PURPOSE: To prevent the rolling of a vehicle body, and to improve riding comfortableness by pivotally supporting front and rear axles in such a way that they can vibrate, on a vehicle body in a horizontal center, and by at least providing a blocking device that blocks the vibration of a front axle in such way that it may be released.

CONSTITUTION: In the case where a vibration retraining device is used for a wheel loader composed of a vehicle body 6 comprising front and rear frames 4, 5 and the like, and of a vehicle main body 1 provided with front and rear drive axles 7, 8 and the like, the front and rear drive axles 7, 8 are supported in such a way that they may vibrate horizontally, on the front and rear frames 4, 5, by supporting shafts 14, 15 in front-to-back direction, through a pair of front and rear supporting devices 12, 13. A front drive axle vibration blocking device 24 is also provided, which is composed of a pair of right and left guides 25, an engaging body 26 as well as an operational cylinder 27, and a control valve 28 thereof, and so on. When a scooping work is to be carried out by a bucket 38, a piston 30 of the operational cylinder 27 is proceeded, and the engaging body 26 is engaged between right and left sides of the front frame 4 and an axle housing 16, and the vibration of the front drive axle 7 is thus hindered.