Originally Posted by robk

Each of the two carriers for the pivot balls has 4 screws to secure the pivot ball in place. You will notice there are 2 more holes, one on each side of the ball, which you can put a screw into for tweak control. The screws I use are small machine screws, I think the size is 1.5mm or 2mm, I haven't measured them. The tweak screws go into the pivot ball carrier towards the front of the car.