Abstract: A torque transmission shaft assembly for connecting a drive shaft and driven shaft which are mutually spaced less than the length of the assembly. The assembly includes a rigid elongated hollow rod member having a body portion and first and second open end portions. Each end portion is adapted to receive either the drive or driven shafts, and is provided with internal involute splines for mating with corresponding external splines on the shafts to be connected by the assembly. The first end portion has an axially displaceable stop member and a biasing spring compressible by displacement of the stop member away from the open first end, for biasing the stop member against the shaft received in the first end portion. The second end portion has a rigid stop at the end of its internal splines, for abutting against the end of the shaft receivable therein.