Have you performed front and rear differential service lately? Also check to see if they need differnt weight fluid for towing. Just perfom all normal services, tranny, diffs, power steering, radiator, A/C, and anything else you can think of.
You don't want any of htese things to let you down on the trip. Make sure you air up all the tires including the spare and trailer.
Retired Navy Submariner
2014 Itasca Sunstar 35F; 5 Star tuned; 2014 Jeep Cherokee TrailHawk