So, I hooked up the 35 ft 5th wheel that is 15k and pulled it up to my families property. This is my first long pull with the truck. I had my edge j/a on the tow setting. It did great on the freeway, awesome up the canyons where the speed limit was 55.. Pulled like a champ.. Then I got to fairview canyon.... This canyon speed limit is 35 mph and is 10-12% grades. I started going up and my trans and motor was getting hot (215 trans motor 225 or so) because the torque converter wouldn't lock up( i was going like 20mph).. I pulled over and had to put my truck in 4 low and turned the chip off so I wouldn't kill my trans, I tried to start going again and it felt like my truck had no power until 2300 rpm or so and then it would get going.. I had to pull the rest of the canyon (12 miles) in 4 low going about 20 mph 3rd gear (the tc was locked) with the rpm at 2900 or so.. I only plan on doing this once a year but my question is am I asking to much out of my truck?? Should I really have to go into 4 low to make it up this canyon?? I had a 12 v that was stick that would do 35 easy up the canyon with this load... Yes it was modded but still.. What do you guys think?? It just felt gutless on the low end..