I have a 2003 F250 FX4 XLT with the 5.4L I dont know which transmission it has or even how to figure it out so bare with me please. I recently went off roading with it in 4x4 high, never went into low. I did go into first gear at one point. It was on flat terrain the whole time, no hills just mud and ruts and water.

Now here is the problem, out of 4x4 lockers unlocked I cant get it to shift from 2nd to 3rd. It will go from 1-2 in its normal shift range with no issue noted. At first i thought it might have been stuck in 4x4 just with the light out, I went threw the normal procedures to get out of 4x4 i.e. rev 400-500 feet neutral foot off brake switch for 2x4 fwd.

Now I will say when doing this I would turn around after and when i turned left i would get a loud thud that i could feel from the left front tire area and same for when i turned right just from the right tire area, i dont know if that has anything to do with the shifting issue or if that was just the 4x4 unlocking. If anyone has any idea on what is going on please let me know I am stumped and dont have much knowledge on this stuff to begin with. If you need anymore info on the truck itself let me know and I will do my best to try and find it if I dont already know it.

Thank you

Also I did try reloading my superchips settings to try and reset the shift points and that did not work even went back to the stock setting.

List of after market parts (incase it helps)
BBK Throttle body 75MM
BBK Underdrive Pullys
K&N Cold Air Intake
Superchips Flaskpaq Performance package installed
Fitch Fuel Catalyst
Skyjacker Hydro 7000 shocks
Toyo Open Country M/T tires 285/75R16

 

You have a 4R100 transmission.

the first step is to get the codes read. Don't go to an auto parts store, they can't read Ford transmission codes. Once you have the codes we can help determine what's wrong.

 

Also forgot to mention and I am sure this part is importaint. The Overdrive light flashed for a little bit but after restarting the truck it went away. My buddy at work said it might be stuck to where overdrive isnt kicking in?

I looked in the manual and it said if it was flashing that it had to be serviced right away or may cause damage to the transimission.

Again dont know if this information helped at all

 

flashing light means you have trans codes get those red and come back and mark k will tell you what is wrong and so on