A gear noise preventing device is formed so that, at the time of a reverse gear shift operation, in accordance with a select operation of a shift lever, a first head (61) that rotates integrally with a shift select shaft (20) rotates a second head (62) supported on a third and fourth fork shaft (52), the rotational force of the second head (62) is transmitted to a third head (63) formed integrally with a fifth and sixth fork shaft (53) to axially move the fifth and sixth fork shaft (53). The gear noise preventing device further includes a coil spring (71) that urges the second head (62) in a direction that coincides with a direction in which the fifth and sixth fork shaft (53) moves; and a snap ring (72) that restricts a stroke by which the second head (62) is moved by an urging force of the coil spring (71).