You are coupling a semi-trailer to your tractor but have not yet backed under it. The trailer is at the right height if __________________.

Step 6: Check the Trailer Height
• The trailer should be low enough that it is raised slightly by the tractor when the tractor is backed under it. Raise or lower the trailer as needed. (If the trailer is too low, the tractor may strike and damage the trailer nose; if the trailer is too high, it may not couple correctly.)
• Check that the kingpin and the fifth-wheel are aligned. [Commercial Driver Handbook]