Rear Axle Identification

challenger6pak · Sep 29, 2004

Ok. I feel kind of stupid asking this question, but I don't know what rear axle I have. I just got the bronco.

It is a 67 with a 289 3 speed manual. It has 3.50 gears, 28 spline axles, and a third member just like the 9inch. Is it a 9 inch? What else could it be?

How can I identify?

thanks,
matt

BigNasty · Sep 29, 2004

There shouild be a tag on the rear or possibly a vin sticker on the drivers door that might give trhe ID for the rear, if it hasn't been changed that is.
Regardless, the tag is prolly still on it, get the #s and someone here can prolly tell you for sure

challenger6pak · Sep 29, 2004

No tag on the axle, the vin plate is long gone.

What other axles could it have possibly come with. Just the 8.8?
Is that also a third member axle?

Sorry, I am a mopar guy, this is my first Ford.

thanks,
matt

STLKIKN · Sep 29, 2004

All EBs have 9" 28 spline rear diffs from the factory.
GVWR options could give you;
different size brakes
different size axle bearings.

challenger6pak · Sep 30, 2004

Ok, in my Ford Service Manual it says that the rear ring gear diameter is either 8-3/4 or 9 in. Are both of these ring gears considered a 9in axle?

If I have the 8-3/4 ring can I switch to a 9 inch ring?

thanks,
matt

STLKIKN · Sep 30, 2004

What year is the manual for?? All EBs came with the 9" rear diff.
No other rear axle options were available.

challenger6pak · Sep 30, 2004

The Manual is for a 67, the correct year, and it is listed for the Bronco, not the Econoline or RV.

STLKIKN · Oct 1, 2004

Hmmm, missed the "Ford" part of your service manual post.... sorry.
I have no idea why they would mention an 8 3/4 ring gear for the rear, neither of my manuals do. Only the nine inch is listed for the EB.
Your truck would not have had a vin plate/ sticker on the door jamb.
It would have been on the glovebox door, or in the case of the 66 and some early 67's the vin was located just above the e-brake pedal on the kick panel.

Guest · Oct 11, 2004

look at the bolts that hold the backing plate for the brakes on if they are like a 3/8"stud it has the big bearing rear end.

S_bolt19 · Oct 14, 2004

They never put a big bearing under an EB until like 74 or 75. A 60's vintage EB will have a 9" in the rear with most likely a Dana 30 up front. If the tag on the 9" is gone and so is the VIN tag, then there really isnt a way to tell what the gears are without opening it up. But I bet it is a 3.50 ratio.

custom_78 · Oct 15, 2004

Someone could have swapped in a Ford 8". I don't know the size of the ring gear but you most likely have a 9". 8.8's didn't come around until 86 and they don't have a removable third member

Quick & Dirty · Nov 1, 2004

The Ford "8 3/4" is just a 9" with a slightly smaller ring gear. Otherwise identical, and regular 9" parts can be used for a rebuild.

Here is a page with pictures of tags, including one from a Bronco with the 8.7" ring gear.

http://www.fordmuscle.com/archives/2002/02...ch/index3.shtml

Here is the start page of the article, a good read about 9".
http://www.fordmuscle.com/archives/2002/02...nch/index.shtml