Well a follow up to my post. The situation with my FR was this: The underbelly has a frame outlining the bottom of the entire T.T. It is untreated wood and is 1"x 4" . The plastic under belly is attached to that wood frame. After examining the "sag" area, it was determined by both myself and then the tech at Southern RV, the wood framing was only attached to the TT in a few areas by screws.
No rhyme, reason, uniformtivity, spacing, etc. Over the two years of use, what was not supported just began to sag! Took off the plastic edge guard.........used self tapping screws and made the repairs.
It really is disappointing what comes of the assembly line of our factories !
2012 Ford F-150 Ecoboost, Screw, H/D, 3.73
1930 lbs CCC
2010 Flagstaff 26 RLSS (Sold 05/16)
2014 Jeep Rubicon JK