PURPOSE: To make a E/L speed change stage compact by providing a linking mechanism to interlockingly shift a shift fork for E/L.5th speed to a 5th speed side only when a shaft head for reverse 5th speed shifts in another direction.

CONSTITUTION: A reverse selecting operation shifts a head 3 for reverse 5th speed to a 5th speed side, and linking mechanism 20 interlocks only in this case to shift a shift fork 13 for E/LW5th speed to the 5th speed side. A E/L selecting operation done at extremely low speed in this condition causes a preventing plate 8 for double engagement to allow a E/L shift heat 7 to shift light from a N position, and a sleeve therefore engages with a E/L gear though an arm 14 and the shift fork 13 for E/L.5th speed to make an E/L operation practicable. Thus a E/L speed change stage can be smoothly switched into another speed change stage by the above compact formation.