It is tightened up the whole way pretty much, the spring is very close to be fully compressed, maybe 1/4 turn, even the manual isnt that far off that setting as standard anyway, obviously you can get away with that a little because its 4WD.
I'll try the extra torque pads that Welshy40 suggested.
I am starting to think some of it was my fault for not cleaning up the slipper hub before fitting the new pads but better pads cant do any harm. Fingers crossed