output shaft 37 u2032 and a part of the oil flows along an oil path designated as a reference numeral 87 in fig1 and lubricates the peripheral surface of the output shaft 37 u2032 for rotatably supporting the follower gears 43 and 44 and a engaging portion of the clutch slider 47 as shown in fig1 and 18 a lubricating inlet 82 is disposed just above the trough portion 24 therefore when a cap 20 is taken off and lubricating oil is run in through the lubricating inlet 82 all the lubricating oil falls into the trough portion 24 a part amount of the lubricating oil can surely reach the groove 78 through the oil leading hole 76 and the connecting hole 77 and can lubricate the bearing supporting the output shaft 37 u2032 and so on in this structure even if components e g the bearing for supporting the output shaft 37 the follower gears 43 and 44 the clutch slider 47 are not spread with the lubricating oil in advance of assembling the transmission 4 u2032 these components are surely lubricated by only running the oil in through the lubricating inlet 82 after assembling the transmission 4 u2032.