Thanks for all of the suggestions...I still have the play but the "clunk" is gone I suspect that I had a loose hub on the drivers side.

Down here in Johannesburg

Once going very slowly backwards I heard a clunk when I put on the brakes. Oh dear a broken spring. If you are replacing anything make sure you replace one of whatever on both sides.

Jack it up. put the emer brake on and turn the drive shaft both ways by hand.

Should let you know where the slop is, might be as simple as a worn u joint.