Control & OperationQuestion 71 of 120
Before backing under a trailer, how should the trailer height be set?
a.Slightly lower than the center of the fifth wheel so the trailer is lifted a little as the tractor backs under
b.High enough that the fifth wheel passes underneath without touching
c.Exactly level with the top of the fifth wheel
d.As high as the landing gear will go
Explanation
A trailer set slightly low is raised as the tractor backs under, which ensures the kingpin engages the jaws properly. A trailer that is too high lets the tractor slide under without coupling or strikes the nose, and exactly level or fully raised risks a missed or damaged coupling.
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