How to tell if it is a Ford 9"

[TOW'D]

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

[Itoldyouso]

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

[cffisher]

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

[Dave Severson]

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

[TOW'D]

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

[Itoldyouso]

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

[Matt167]

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"

[TOW'D]

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

good info
cheers
hank

[IC2]

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)

[stovens]

Do they make aftermarket covers with drain and fill plugs?

[Matt167]

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.

[Matt167]

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.

[hawk56]

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