Replacing corners, tailgate gaps

[finorman]

I'm in the process of replacing my corners as well as the rear roll bar pans. The PO had replaced the corners, but the tailgate gaps are off on both sides... when I put pressure on the bottom quarter panel and lift up, it adjusts and fixes the gap for the tailgate, but I can't tell what I need to do to keep it "up". it almost feels like the quarter panels are sagging.

I checked to see if the cross member that goes under the rear roll bar pans is level, and that is good to go. Before I weld the floor pans in I wanted to see if I needed to do anything to get rid of the quarter panel sag.

Is this is common problem? Does anyone have a suggestion for a fix? Thanks in advance.

 

[Craner8]

I’m no expert. Start with that. Are the brackets secure on the rear quarter panels like bracket picture three? Maybe put a ratchet strap across the back and pull the quarter panels together? Maybe jack and 4x4 lifting quarter up? Shims? Not sure that would keep them from returning to their original position though. Height looks good compared to top of tailgate.

 

[Mancunian]

Check the body mount rubbers and the crossmember, if the bodymounts have collapsed you might get this problem

Without it being tacked in there's really nothing to hold the corner square - you could try as Craner8 suggested and just lightly tack into position and see if that fixes the problem

 

[finorman]

I think you are all onto something. I think if I push up from the bottom of the side qtr panel, medial at the top of the rear of the corner and out with the bottom, then tack weld where the yellow dot is located might do the trick.
As you all suggested, then maybe weld in the rear roll bar floor pan.