Hi Norm,thanks for replying.
It is the simplest of designs. End of the crank has a sleeve with a square hole (have had a good look, its not worn). The flexible drive shaft then goes to a coupling on the head end.The flex drive and and its housing are new. I have been thinking that maybe the flex drive is moving back away from the head end,but once its put together there's no way to check.The hex drive a the head end is new, the head coupling is good.The old flex shaft is stuck inside the housing. I"m going to cut the old housing apart just to see whats inside at the head end.
