I have a 2004 4x4 with a 5.4 triton, 3.73 rear axle and cummy pulling ability in 2whi. I pulled back home in 4whi and found out thats a no no. what if anything can I do to help me pull my empty toy hauler? (4500 LBS). 3% grade floored 45mph

 

Somethings wrong with your truck! I tow 8500# on a regular basis. My TT is 33'-11" long and tows like a dream. I have pulled it up 7-9% grades. It is slow on that grade but pulls it. I usually tow at 63 MPH with OD locked out and get between 9-13 MPG while doing it. I would seriously be looking for something wrong with your truck.

 

Yeah you've got some issues, my 02 pulls 6k up 3% at 65. are you turning off OD? you shouldn't pull up grades with your overdrive on.