18f? When those were made Jayco was still using Dexter Torflex axles on the hybrids. Both our 2003 Kiwi 17a and our current X20E have them. They are not leaf springs and cannot be flipped.
They can however be raised on some models. In fact Jayco was offering a 2" lift kit on some of the hybrids for a while.
Some people have made their own lift kits. Search here for "axle lift".
Here is one that may be helpful.
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Chuck
2013 Jayco Jayfeather X20 E (sold)
2016 Chevy Silverado LTZ 2 Z71 Crew Cab (sold, and dearly missed)