The receiver hitch sold by the Jeep dealerships is only a 1.25" in an attempt to keep the towed weight down. Replace the entire hitch with one with a standard 2" receiver hitch. For the $$$, you may want to consider a new rear bumper that has an integrated 2" receiver hitch, they're not that much more than a U-Haul or Reese bolt-on receiver hitch. Olympic makes a nice bumper with an integrated 2" receiver hitch and is what I've been using for years now. You can see it in a few pics on my website, below.