a shaft member connected to a drive fitting yoke by a joint member is splined to a shaft member connected to a driven fitting yoke by a joint member . a spring accommodated in a hollow chamber continuously extending through the shaft members axially biases the shaft members away from each other . limiting means for limiting the maximum length of extension of the shaft members prevents the spring from exerting a thrust load on the drive shaft element and driven shaft element interconnected by the drive shaft . the spline coupling portion has an increased diameter to ensure the strength of the drive shaft .