How much space should be between the upper and lower fifth wheel after coupling?

Having no space between the upper and lower fifth wheel after coupling is critical for ensuring a secure connection between the tractor and trailer. This close contact means that the coupling components, which include the fifth wheel plate and the trailer's kingpin, are properly aligned and engaged, allowing for safe operation and preventing any unwanted movement during travel.

When there is space between the fifth wheel components, it can lead to instability and potential disengagement while driving. A tight coupling also enhances the stability of the load, which is especially important when maneuvering around corners or navigating uneven road surfaces. Achieving no space is a fundamental part of the pre-trip inspection and coupling process, emphasizing safety and reliability on the road.