If the front of the vehicle has settle more than the rear you will need to increase the aount of working links. If more links are not available, remove the springbars, remove the caravan from the vehicle and adjest the cams to change the angle of the towball towards the vehicle.
If the rear of the vehicle has settled more than the front you will need to reduce the amount of working links. If the minimum of 4 links is already being used, remove the springbars, remove the caravan from the vehicle and adjust the cams to change the angle of the vehicle.
Folllow the springbar installation process to refit the springbars and measure the vehicle and caravan again, if they have still not settle evenly then readjustment of the ball mount head on the shank will be required to achieve the correct heights.
Once the correct setup has been achieved tighten the two M19 bolts on the head to 190 Nm.