Steeringbox acting strange…

When I turn the steering wheel there's a strong(!) "brake" feeling in the wheel just about when I've started turning left, & when I keep turning it goes easy again...
& yep; I've lifted the front clear from ground.
At first I thought there might be dirt inside but why does it only apear at the same spot every time??? Box looks like this:


SterBox.JPG
Author: Glider