My 07 Cherokee has a GVWR of 11,200 lbs. it came with load range "D" tires on 5k lb 6 lug axles. My trailers dry weight is 7100 lbs. either someone swapped out the axles for the wrong ones (doubtful, but not impossible), or more probable is that is how it was built! And seeing as how the axles have an 05 date code it is very reasonable to believe those are the axles it was built with!
Regardless, they need to be swapped out with the right axles and you need to step up to 15" wheels and "E" rated tires.