bill-e wrote:
Cant use a weight distribution hitch.
Not true, 2009 onward - not sure about prior to that. The owner's manual says it's not recommended because you might set it up incorrectly. FWIW, the issue is that one could overload the front axle if not careful. The front axle in the '09-'15 model years can only handle a full payload plus another 2-300 lbs of additional weight. I don't know about the '16. So, weigh the tongue, and move a proportional amount of the spring compression to the front, not to exceed a couple hundred lbs worth, get weighed when fully loaded (front and rear axles separately) and make sure it's still under.
Yes, you also have to have the tranny cooler to get the 5K tow rating. It came standard with the 4wd versions for some model years.
If used within it's limits (just like my Sienna) the 2009 and later model years have proven to be very capable, reliable, and comfortable tow vehicle. There are forums specifically for the Pilot and Ridgeline (and Odyssey, which has the same limitations as my Sienna) where one can talk to many people that have towed for many years and miles with them.