If you are not holding onto the steering wheel when the vehicle is travelling forwards and the tracking pulls the car to one side, this is called oversteer/understeer.

"Oversteer is a phenomenon that can occur in an automobile which is attempting to turn. The car is said to oversteer when the rear wheels do not track behind the front wheels but instead slide out toward the outside of the turn. Oversteer can throw the car into a spin. The effect is opposite to that of understeer."

This has to do with how much 'play' there is in the steering wheel for the truck. If one has to "drehen" a good deal to keep the truck going straight, that's the term

This is the term used when the "Schläge" are periodic. Although Mike is right the "a" Schlag is never period; a number of "Schläge" in a row certainly can be.