i have a 2005 F150 FX4 4 I am trying to find out if i have a 9.75 or a 10.25 rear diff and there is no tag. I am going to replace the rear fluid and i want to replace the cover also. It is a B6 rear code. I know it is a 3.73 ratio.

Any help.

 

It's probably the 9.75.on a fx4.
you won't have the 10.25 unless you have 7 lug wheels.
The 8.8 and 9.75 are the common options, the 9.75 has a trapezoidal cover with 12 bolts, the 8.8 has a more oval shaped cover.

 

Ok, i have 6 lug, i know the covers between the 8.8 and the other two, but the 9.75 and the 10.25 are about the same, just size difference.

 

They did not put that 10.25 Sterling in a F150
Here is a cover plate Identification from Summit
True, hard to tell sometimes
There is a slight shape difference in the bolts and cover between 9.75 and 10.25

 

Ford 9.75

Ford 10.25

 

Shows up in both the owners manual and the ford service manual.

 

That owners manual is for F series not F150
I stand by no 10.25 in a half ton ever
Too wide, most were full floater and they all had 8 lug hubs
Show me one

 

Although some 2005 F-150s did come with a 10.25 gear set, with a 3.73 ratio you would have the 9.75 gear set.
Only the Heavy Duty Payload Package with 7 lug axles and a 4.10 ratio used the 10.25 gear set.

Heavy Duty Payload Package – Increases GVWR to 8200 lbs.
for improved payload and towing. Includes LT245/70R17D
all-terrain BSW tires; high-capacity 17" 7-lug steel wheels;
heavy-duty shock absorbers and 72-amp.-hr. battery; springs;
upgraded radiator and auxiliary transmission oil cooler; 5300-lb.
rear axle with 10.25" gear set and 4.10 axle (Regular Cab and
SuperCab only)


https://www.auto-brochures.com/makes...F-150_2005.pdf

 

incorrect.

show you one? okay, a quick google search gives several boneyard listings for the 4.10 ratio, 7-lug, 10.25" sterlings that were part of the Heavy Duty Payload Package. here's links to three - and there are plenty of others. they also show the junked F-150's that the axles were pulled out of.

and the two guys above have already provided documention from ford showing that it was available on these trucks.

so that's bad info you're putting out there


https://www.ebay.com/itm/144329978961

https://www.ebay.com/itm/225288849487

https://www.ebay.com/itm/394370343997