To provide a synchronous meshing device for a vehicular parallel shaft type transmission inhibiting generation of abnormal noise and drop of drivability due to backlash formed by formation of a tapered surface in synchronous meshing devices for vehicular parallel shaft type transmissions having tapered surfaces for preventing mutual gears from coming off formed on sleeves and gear pieces.

Outer circumference teeth 46 include first outer circumference teeth 46a capable of contacting both of acceleration side tapered surfaces 60 and deceleration side tapered surfaces 62 of inner circumference teeth 32, and second outer circumference teeth 46b capable of contacting the acceleration side tapered surface 60. The backlash L2 is determined based on a shape of the first outer circumference teeth 46a. The second outer circumference teeth 46b is formed in such a manner that contact area in contact on the acceleration side tapered surface 60 is larger than the first outer circumference teeth 46a. The backlash in a rotation direction is reduced according to the shape of the first outer circumference teeth 46a, and reduction of shock and abnormal noise and improvement of drivability are achieved by such a construction.