Anybody got any idea why my gear stick rotates when you lift it to select reverse? Haven't pulled it apart yet and the Haynes manual is not very helpful.......

There's a pin in the housing and corresponding slot in the ball that the gearlever pivots on, that should prevent the lever from rotating. I would expect will find some wear when you get it apart.

Sometimes it is wear on the slot on the ball of the gear stick.
Sometimes the press fit pin slides too far out and does not engage in the slot.

So remove gear stick and look for pin then?