SugarHillCTD wrote:
Nice setup.
I have a front hitch and carrier. A few weeks ago I tried one of these

and we were fine until we had to climb a few hills- then the trans temp really started to climb. On the 2500HD, the trans cooler had its own bumper opening, just below the grille. The box is blocking off too much air. Have to rethink/reconfigure.
This may or may not help but out of curiosity, did you have the truck in tow/haul mode? On my last trip out west I was climbing one "hill" with lots of switchbacks and the tranny temp really started climbing. I enabled tow/haul to lock up the torque converter quicker and the tranny temp dropped.