I have a 2001 F-150 screw with the 9.75 rearend, 5.4 motor and it is 4x4. does anyone know what gears come standard in these axles and if they are a 31 spline axle???? Any help would be greatly appreciated

 

Check your sticker on the inside of you door jam. Then reference this below and it should tell you what you have. I think there is a "sticky" thread on here somewhere that has all the axle codes but this is all I could find as I only did a quick search.

Axle Type

19 — 3.55 non-limited slip — F-150
25 — 4.10 non-limited slip — F-150
26 — 3.73 non-limited slip — F-150/Mark LT
27 — 3.31 non-limited slip — F-150
B5 — 4.10 limited slip — F-150
B6 — 3.73 limited slip — F-150/Mark LT
H9 — 3.55 limited slip — F-150

 

thank you so much for the help. I have a 19, so 3.55 gears and non limited slip, unless the rearend has been changed by the previous owner. If I changed the gears to a 4.10 and put in a lmited slip, ho much performance would this add? I am basing peformance off of the fact that the truck is pretty peppy as it is and I am wanting more bottom end

 

4.10's would be a great mod for you truck. Many members have done the same, and with that 5.4 you'll have one smokin truck. It will also perform better with traction if you go with limited slip. Keep in mind that you will have to regear both front and back since you have a 4x4 which can be pricey. I've seen quotes on here from $500 - $1000 per axle.

 

thank you so much for the help....well, with switching the gears to 4.10's plus having the airaid throttle body spacer, pace setter headers, and the cold air intake, this truck should have no problems with performance after the gear swap

 

yeah, you'll really gain some low end torque. Of course there is no HP gains with gears but the seat of the pants power gain is pretty noticable. Just an FYI incase you are going to change tire sizes, I found this link to be quite helpful as well when I did my gears. Good luck man.

http://www.s-series.org/htm/calc/ratiotable.htm

 

I greatly appreciate all the help!!!

 

if you wait another day or two i'm in the middle of switching from 3.55 to 4.10 on my 02 5.4. going to make a DETAILED instruction manual too. everything you find online is crap

 

tat would be great!! I really dont want to pay for instulation if I dont have too. Also let me know how much "seat of your pants" power it gives you Thanks man and good luck