air leaf heights

[alborz]

recently I bought a peterbilt 579
it has air track suspension
the height of fifth wheel from ground is 52"
according to Peterbilt. the suspension level from center of axle to bottom of frame should be
11 3/8" where mine is that high.
every truck I look the the top of frame is just as height of the wheels . (22.5" tires.)
I can't find the problem because the trailer height is about
from ground to top of fifth wheel 52"
roof of trailer to fifth wheel 114"
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166" = 13' 10"