A first and a second rotary member such as outside or inside clutch member arranged as axially juxtaposed and radially expanded to rotate individually about a common axis in a transmission for a vehicle are separately torque-transmittingly connected with a first shaft member and a hollow second shaft member coaxially and telescopingly disposed around the first shaft member to be respectively in an individually torque-transmitting relationship by first external splines formed at an outer periphery of an end portion of the first shaft member axially extending out of an open end of the second shaft member being axially placed into engagement with first internal splines formed at an inner periphery of a central bore formed in the first rotary member, while second external splines formed at an outer periphery of an end portion of the second shaft member adjacent the open end thereof are axially placed into engagement with second internal splines formed at an inner periphery of a central bore formed in the second rotary member.