Thread: How to tell if it is a Ford 9"

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Howdy Gang,
Where do you measure to tell if it a Ford 9" rear diff
thanx
hank

It will have a removable center section (from the front) and the way to tell if it is an 8 inch vs 9 inch (they look very similar) is to put a deepwell socket on the two bottom bolts that hold that center section on. If the socket goes on, it is an 8 incher. If it hits the casting and won't clear (so you need a box end wrench to remove them) it is a 9 incher.

Don

Yep what Don said there is no where to measure to tell as there are MANY different length 9" housings.

http://www.carnut.com/specs/rear.html this may help you

The 9" dimension refers to the diameter of the ring gear.

Thanks guys
I'll try the socket or box end wrench tip
cheers
hank

Hank, just to muddy the water a little, Ford also made a 9.375 rear end that looks similar to the 9 incher. It was used on some T Birds and other big Fords. Here is a pretty informative site on Ford rears:

High Q Ties - 9" Ford Information and Identification

And here is even more reading on the subject:

http://www.fordification.com/tech/rearends_ford04.htm


Don

and to add to confusion. if it's a pulled axle, there is a chance it is a Toyota axle. They used dropout centers just like the Fords and the 2wd models are 5x 4.5". they measure about 8"

Thanks
Don for the axle id code
Matt for adding to the confusion

good info
cheers
hank

Then if you really need more confusion, GM used a drop out differential in the '55-'64's and MoPar......'65-'76 (at least those are my "best guess" for years)

Do they make aftermarket covers with drain and fill plugs?

forgot about those lol..

Actually, a few years ago, I saw someone trying to pass off a Yota axle as a 9" on Ebay. There close to looking the same, but the rear 'dome' is larger on a Ford diff.. But even the pinion flange is simmilar on a yota axle.

Originally Posted by stovens

Do they make aftermarket covers with drain and fill plugs?

8" and 9" Fords as well as others that use the front "drop out" design do not have removable rear covers.

Chevy 1/2 ton trucks , 50's and early 60's used "drop out " (pumpkin design ) and they have a removable rear cover ..