My diff cover is rusting away to nothing. I want to get an aluminum cover since I tow a trailer sometimes and I just like to upgrade when I replace stuff.
My truck is an 05 F150 FX4 Supercrew 5.4, 3.73, 4WD limited slip rear, 12 bolts. Is my diff a 9.75" ring gear? Is it a Sterling? I know enough to get 75W140 and limited slip additive, I just want to get the right cover and the right amount of diff lube which is determined by the diff type.
Who knows the scoop. I ain't that smart about this stuff.

 

from what you said it sound like a 9.75. go to randys ring and pinon and compair it to the pics there

this is the one i want. its from top cun customs

 

all set, found the diff tag. I'm good

 

That is nice!! What is the price tag for that?

Oh yah, easy way to tell diff's. 10 bolts 8.8. 12 bolts 9.75

 

The 12 bolt 10.25 (f250) looks exactly like our 12 bolt 9.75 , just slightly larger .

 

$220 i think