Well, I came across a Craigslist Ad today for what was said to be a Ford 9" rear end out of a 1963 Ford Squire Country Wagon. The guy was local so I ran over to take a look at it. I am not a guru when it comes to these things, but the things that I had been told to look for made me feel comfortable in paying what he was asking for it. I brought it home and began to research the tag information. The tag id is WBT AU 1, 3 50 3CB 100. If my research is correct, then I actually have an 8 3/4" rear end, not a 9". What are your thoughts? How does this rear end compare to the 9" how much less valuable is it?
If its an 8 3/4 MoPaR Rear end ... In my Opinion you have a Better rear end than any Standard run of the Mill 9" Ford. Never heard of an 8 3/4 Ford axle
If you can use a socket on the bottom two nuts holding the carrier to the housing it is NOT a 9 inch. If you have to use a wrench to remove then it IS a 9 inch.
Ford called some of the early 9" rears 8.75" even though they're a 9" as far as we can tell. If it has a removeable center section, and you can't remove the lower two nuts that hold it to the housing using a socket (you need an end wrench), then it's a 9".
I have been through this before. Bought a rear end I thought was a 9" but the ring gear measured less than 9". Everything looks the same from the outside. I'm sure if you know how to read the tag the info is on there.
It's a 9".....i have the same in my truck, it is the older (and slightly weaker housing) is the pinion seal leather?
An 8-3/4" is for all practicle purposes a 9"..Only real difference is the ring gear bolt size, 7/16 vs 1/2..A 9" carrier can be used with an 8-3/4" ring gear but the bolts are special with a 1/2" dia shoulder for the 1/2" holes in the 9" carrier..Whole chucks can be interchanged..There is also a 9-3/8", not much in perf gear but a 9" chuck will interchange..As long as axle splines match carrier splines your set..
8-3/4" is the standard Ford diff that was used in Australian Xw-Xy Falcons, they were also used in some Mustangs. They are considered a 'Light duty' rear end and are weaker than a 9", but unless you are going to put some serious Hp through one it should be fine. I have heard that there is not a good range of ratio's available. I ran one in my old A RPU, had a bog stock 302 and that diff was fine never had a problem with it. Pretty sure thats not one though. Doc.
But wait! There's more! The housing is only clearanced for the 8 3/4 ring gear. You will find that the carrier is 28 spline and is not bored large enough to permit use of 31 spline axles. (later units would allow 31 spline if you swapped ou the spider gears or used a mini-spool, etc.) The carrier will not support gobs of power, so any upgrades usually involve tossing the entire center section for a later unit. To get a later 9" unit to go into the housing, you will need to grind clearance in the mounting flange where the ring gear p***es through the hole. Once it's in, there's no concern, but it won't go in without a little grinding. Last, be gentle with all the brake parts. They are dang near impossible to replace. There are only one or two options for small bearing drum brakes and most anything else requires changing the housing ends. In short, it's a good value if used as is. After that, it's an expensive way to get a 9", but the round back is usually very sought after by guys that will have it visible under their early hotrod.
Pictured is a Ford 9 . If its an actual out of a Station Wagon unit it has the 88128 axel bearing and large axels and is a good unit. There is a huge selection of ring and pinion gears on Ebag from NASCAR sellers if you look and price is right. It should also have the large brakes and parts are still available for it.
also notice the only way to fill the axle with grease is through the housing (no fill hole on case) you can drill and tap for a plug if you put it in another housing,,,
If it is the early ('57-'59) rear it is indeed an 8 3/4 rear. I don't have a list in front of me so I can't tell you what it is. But if it is a smooth back it is a '57 and if it had dimples it is a '58-'59. The upside to that is that the 9" chuck goes right in no problem. So just fond a 9" chuck and you are good to go. There is some information and pics on this thread. http://www.jalopyjournal.com/forum/showthread.php?t=535819
I know for a fact that a later 9" "chuck" will not fit in a '57 housing without some clearance grinding of the mounting surface for ring gear clearance. '57 (and I believe '58-'59) dropouts had a ring gear that was less than 9" in dia, whereas the later units were a true 9" dia.
Just get a new gasket and put it up to the housing. Mark the spot that needs clearance and grind away. Then any 9 inch center section can be bolted in. No big deal.
Bolted a late chuck in a '59 case last year no grinding. Maybe the '57 had a thicker flange. Ford used an 8 3/4" ring through '59.
Is it a good gear ratio? if it is then use it, who cares if its 9" or 8-3/4, it does the same job, if your gonna rebuild it it uses the same parts, so what does it matter?? And if the ration isnt what you want just get a newer carrier, then they dont have the stupid big diameter pinion seal. JEFF
If the tag is correct (and the website I listed earlier is correct), then the ratio is 3.50 and it is out of a '63 P***enger Wagon. To everyone who has chimed in on this topic, I really appreciate the information.
If it is out of a '63 wagon it should be a 9" I wasn't aware that they were still using the dimple housing past '59. Never the less you should be alright.
May just be the '57 housings... I know that nothing ****es up your under car vocabulary more than finally getting the 3rd member wrestled into place just to find out that the ring gear wont clear the housing!!
Great thread. I was wondering the same about what is on my car and now I can verify with the help of everyone that wrote here.
Yes.... Good info, I have a 59 T-Bird 9" I am gonna use.......Whats the difference in brakes, t bird rear is missing all hardware and drums but i have another later set. is it just housing end pattern?
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