Chris Alcala
Member
We know the 3.5L EB will handle north of 13,000# on a "properly equipped" F-150. But the 10-speed transmission seems like the weak-link in these late-model Expys. Not sure how hot your 06R70 gets towing those numbers of your camper ...but I'm only 6200# (GVWR) and my '19 (with HD tow) got all the way to 245F ...and they apparently go into limp mode at 250F.
The 10-speed doesn't seem to be built for the extremes of super hot weather ...unless you wanna drive it at least 10 below the posted speed limit.
I have never been above 215F on my trans. That was on a trip through the Texas Hill Country fully loaded in July.