Im trying to figure out what the gear ring size is on the rearend of my 07 f150 fx4 , the axle is h9 gear ratio is 3.55 , the metal tags that are supposed to be on the differential aren't there.. everything I've search all suggest its the 9.75 just looking for some way to tell without tearing the plate off and looking at the gears themselves

 

What engine do you have? I think the 5.4s came with the 9.75 and the 4.2/4.6s came with the 8.8. Visually, the 8.8 is a bit more square (with 10 bolts instead of 12).

9.75


8.8

 

Shoot me the last eight digits of your VIN, I can tell you what Ford put in it. I am leaving for the weekend shortly so may not reply until Monday.

 

its the 5.4 and mine looks the top pic

 

its 5.4 snd mine looks the one in the top pic

 

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