how do i tell what differential i have?

[atle]

hey guys, sorry if this has been answered before, i'm at work and don't have alot of time to search. i have a 2001 XLT 4x4. i need to change the differential cover and gear oil. how do i tell if i have an 8.8" or 9" rear? i see a big 9 stamped on the differential cover, is that an obvious give away? i don't know. the axle has a 939P sticker on it as well....

thanks in advance.

 

[atle]

got it. Axle H9 = 8.8 3.55 gears

trans E = 4R100 ???? or E40D ????

 

[FordandPolaris]

E4OD's were only found in 97-98 models, so you should have the 4r100, although I do not know my tranny codes by heart.

 

[atle]

thanks! you are correct with the 4R100.

i wonder if the differential cover for the 8.8 and 9.75 are the same???? I'm looking at the Mag Hytec website and they only have a 12 bolt 9.75 cover, not a 12 bolt 8.8.

 

[FordandPolaris]

What rear end ratio is in my Ford , do I have positraction? - Drivetrain.com

Forgot I had this bookmarked. It is not a complete resource as it is missing the 3.73's (H6 code) as well as the 9.75 cover as far as I can tell. However it does say that the 8.8 has 10 bolts, so I would assume the 12 bolt cover you are looking at is for the 9.75.

EDIT: After some reading, the covers are definitely not the same. You will want to try and find an 8.8 (10 bolt) cover. Look in F-150 parts lists for the 4.6L etc. That engine was much more common in the pickups than in expy's, and they were often paired with the 8.8 from what I can tell.

 

[atle]

thanks for the link. very helpful. i did count the number of bolts and it is 12 ! and the cover is not round like the 8.8 10-bolt. what i'm thinking is that my expedition came with the tow package, so that would beef up the rear to a 12-bolt 9.75 ??? i hope so ! but then the door sticker code is incorrect

 

[FordandPolaris]

Look behind your front bumper, if there is a small radiator in front of the normal one than you should have the tow package. That is a transmission cooler.

 

[whowey]

Do a quick search for my user name and threads I started. I just did the same thing about 2 months ago. You will see the info there.
The 9.75 cover looks like an old Dana 44 or Dana 60 cover. the 8.8 is round-ish with squared off sides.

Ford 9.75



Ford 8.8

 

[atle]

thanks a bunch guys. definitely have the tow package and 9.75 rear. NAPA has a cover that I can pick up tomorrow for $28. I will save for a Mag Hytec cover in the spring.

 

[toms89]

8.8 is tiny compared to the 9.75 rear!!

Just an observation....lol.

 

[FordandPolaris]

In the picture of the 9.75, I was thinking there was an awful lot of light under there and it must be on one hell of a lifted truck, till I realized there is no truck above it! Its just the frame haha.