The coupling pins of your trailer hitch have a diameter of 38 mm when new. What should you note regarding wear?

Your selected answers are correct and reflect important safety regulations regarding trailer hitch maintenance.

1. The requirement that the diameter may not fall below 36.5 mm across the entire extent of the coupling surface is essential for ensuring that the coupling remains secure and can handle the loads it is designed for. If the diameter decreases too much, it can compromise the ability of the trailer to stay connected safely.

2. The stipulation that the lower pin guide should not exhibit any excessive free play is crucial because excessive movement can lead to instability and increase the risk of the trailer disconnecting while in motion.

Together, both conditions help to ensure that the trailer hitch functions correctly and safely, preventing accidents and ensuring compliance with German traffic regulations. Always maintaining these standards is vital for road safety.