I didn't have a speedy sleeve so replaced the flange bit that the universal bolts to which fits on the splined output shaft. I think that came from Don Kyatt also. The centre nut is a bit special. 36mm castellated and flanged (on FG649). Broke a breaker bar trying to undo it. Neighbour's rattle gun worked. The nuts/bolts for the flange cost arm and leg, I used Nylok - deeper than original but there was enough room.
Cause of my failure was possibly the very worn splines in the drive shaft. I could feel the vibration. If not the cause it contributed. Had it rebuilt (and lengthened a bit to compensate for spring height) by Hardy-Spicer in Darra.