What are you towing with a F150 thats 14k lbs?
I am curious on the profile of the trailer etc. I have a f150 that tows 6k enclosed trailer like crap. Not the engine, the chassis. I am not using WD hitch though.
It is also my first half ton truck in 15 years, so maybe I was expecting too much.
16 1/2 ft deck over trailer, with tractor and mower, comes to a little over 14K#. Load positioned for proper balance/tongue wt. As I said, I spec'd the truck out to pull. 3.5 EcoBoost, longer wheel base 6 1/2 ft box, HD towing, 3.55 gear, LT tires, etc. Works very well, as it's spec'd rated to pull right at 13K. I don't pull that everyday by any means, but when needed no hesitation. I suspect you using "P" series tires? Not good for towing.