Ford 9"?

Ghost

Member Number 257
NAXJA Member
Location
Camden, SC
Ok got a couple questions on the Ford 9". First I have noticed that they are availabel in 28 and 31 spline versions. i have also seen 33 and 35 spline spools and lockers available. Are the axles shafts any larger on these different versions or is it just different spline counts? Would a 9" shaft at 28 splines be considerably stronger than my POS D35? LOL I know dumb question there! In other words would it be worth buying a 9" axle with 28 spline shafts and swaping it in till I can get the bigger shafts? What is the consensous on mini spools vs lock-right or other lunchbox lockers? IIRC several of you run the 9" and I would appreciate your experiences.
 
I would go for it. Later on you can swap in 31, 33, 35, or even 40 spline shafts. Pay attention to the bearing size at the housing end, it can make a difference in how large of shafts you can run. You get the housing setup for your suspension, then you can swap shafts and third to your hearts delight, they're bolt on then. I'm not sure if the 33 splione shafts are larger, pretty sure the 35 spline shafts are 1.5" diameter.

I'm in the process of setting up a 9" for my XJ. Funds are non existent right now, need some parts to get discs mounted and working.
 
Static-XJ said:
I would go for it. Later on you can swap in 31, 33, 35, or even 40 spline shafts. Pay attention to the bearing size at the housing end, it can make a difference in how large of shafts you can run. You get the housing setup for your suspension, then you can swap shafts and third to your hearts delight, they're bolt on then. I'm not sure if the 33 splione shafts are larger, pretty sure the 35 spline shafts are 1.5" diameter.

There are two Ford housings, big bearing and small bearing. These refer to the outer wheel bearing size and not the carrier bearings. There is only one OEM bearing size for the carrier (3.0625" I believe) and they are all cast iron cases. I have heard that some late 60s muscle cars got nodular iron cases and may have had larger carrier bearings, but for all intents and purposes, they don't exist for us.

The largest shaft you can run with the OEM cast third member is a 33 spline and your only carrier option is a full spool. The shaft dia on a 31 spline is 1.31" and 1.50" on a 35. I would say a 33 probably falls somewhere between. The 40 spline is 1.72" in dia.

In order to got to either a 35 spline or 40 spline, you will need an aftermarket nodular iron center section like those made by Strange. These have a 3.250" dia carrier bearing and are not cheap. You will also need a new pinion support. The complete third member to use 35 or 40 spline shafts will probably run you around $500-$600 alone.

Your only carrier option for 40 spline is a full spool.
Detroit makes a 35 spline locker and full spools are also available. ARB is rumored to be producing a 35 spline locker but I would be very cautious getting one. Due to the rather small carrier size of the 9 inch, ARB actually had quite a few problems with their first 31 spline lockers. I can only imagine those problems would be compounded on 35 spline version.

If you're going to make the upgrade to a 9 inch, go with the 31 spline at least. Custom shafts with bearings are only about $300 from either Moser, Strange or Currie. If you find a housing that's the right width, but it's 28 spline, just ditch the shafts and get new 31 or 33 spline units to match your new 31 or 33 spline locker or spool.
 
Ghost, unless you can get that 9" for free or nearly free, just look for a fullsize 9" out of an F-150 or Fullsize Bronco from the mid to late '70s. Yes, they're full width, but the housings are already SOA and set up perfectly for a direct bolt-in to an XJ, and I believe they add an additional 1.5" of lift or so, but I don't know that for sure. They also have the big bearing ends and 31 spline guts. From what I hear, 9"s are super easy to shorten too, so it won't be too costly for you to have the housing and shafts shortend.

HTH.

Jason.
 
Economos said:
set up perfectly for a direct bolt-in to an XJ,

Jason.

Jason, are you saying that the width of the spring perches is the same as XJ width on these F150 9"? If so that it cool, I did not know that.

I have built two 9", on in 31 spline and 1 in 35 spline. CROK pretty much nailed all that you need to know.

9" housings should be pretty damn close to free. Mine was laying in the mud for quite a while. A MUST is a weld on truss that goes across the back of it because the housing is stamped sheet metal and the axle tubes are either .25 or .188 wall. Truss really strengthens the housing, just be careful welding it on as too much heat will distort the tubes/housings.

I am running a Strange nodular third member that I found on ebay for $220 NIB. The pinion support is another $75. The roundy-round racers have tons of options for thirds and you can spend a lot on all aluminum stuff. Detroit or Spool only, I ditto what CROK says about the ARB for the 9".

I wanted a full float rear on my 9" so that my axle shafts only turned the tires, not support that weight of my rig. Warn makes a FF kit for about $1K. I found an old 14Bolt GM axle and cut the ends/hubs off of and welded these onto my 9". So with 35 spline shafts and 14B hubs, I have a 1-ton axle that weighs a lot less than a D60/70/14B and has better ground clearance. I have the most bad-ass axle never to leave my garage ;)

SeanP
 
This is exactly what I was looking for.

Good reliable info from people that have been there and done it. I had heard that the F150 and Bronco was the same width on the spring perches but have not been able to confirm it. Also, what about the 70's F100 2WD 9's? Would they likely be 28 or 31 spline? When you say big bearing I understand its the end tube bearings but how do I tell the difference? tape measure? What are the two sizes? I got a line on a couple of axles but will not be able to check them out for a little while. $$$ are short right now. But now I know what I need to look for. Also, is it posiable to shave a 9" or is that asking for trouble b/c of the way they are set up?
 
Re: This is exactly what I was looking for.

Ghost said:
Good reliable info from people that have been there and done it. I had heard that the F150 and Bronco was the same width on the spring perches but have not been able to confirm it. Also, what about the 70's F100 2WD 9's? Would they likely be 28 or 31 spline? When you say big bearing I understand its the end tube bearings but how do I tell the difference? tape measure? What are the two sizes? I got a line on a couple of axles but will not be able to check them out for a little while. $$$ are short right now. But now I know what I need to look for. Also, is it posiable to shave a 9" or is that asking for trouble b/c of the way they are set up?
Rough rule of thumb is that all trucks from about the mid 70's thru 85 (end of 9" production at FoMoCo) got big bearing 31 spline units. There are always exceptions, and it may be jusrt 4wd trucks. Big blocks are more likely to have big bearing 31 splines, but some could be a 9 3/8". That is actually what mine is, 4.09:1 9 3/8". It's a slight varriation on the 9", none of the third internals will interchange, and I haven't seen any aftermarket for the 9 3/8" (not even r&p's). I'm using it because it's got the gears I want, and I can swap a 31 spline 9" third into the axle housing. So when I need new gears, I'll need a new third. But the axle housing will be set up, and the assembled third would just need to be bolted into place. Gotta love the modular design. To ID a 9 3/8, find the casting numbers on the pinion support, if you see C8-AW, it's a 9 3/8.
 
Static-XJ said:
I pulled my 9" from a 77 F-150. Spring perches were 3" too narrow to be a direct bolt in under an XJ.

Ok, I may have spoken too soon about this. The one I've heard being a direct bolt in came out of a '78-'79 fullsize Bronco. I've heard this first hand from several guys who've done this swap, so I don't think its SPBOI; I think it depends on the housing.

Ghost, I'm not sure what those 2wd 9"s would be to be honest. I'd bet that its a 28 spline if its out of a 2wd F-100, but again I'm just guessing. I think the late '70s 2wd F-150s might be 31 spline, but I really don't know for sure man.:confused:

As far as clearance shaving - yes you most certainly can. Here's a shot of Wanderingwilly's shaved and trussed 9".

rear13.jpg
 
sweet!

now to start the search. i found a 70 ford at a friends place and am hoping hell sell me the axle cheap. Like $50 or so. We shall see soon I hope. Now to research the shaving thing!
 
Another question for you running the 9"

On another thread I sugested someone look at the 9". And Stryker sugested against it bc it gets hung a lot on the trail. Anyone else experience this? Also I check its out of a 78 truck. I'm goign to pull the wheel and brake drum to check it out. I might be able to get it for 50$ or less.
 
Has anyone tried a 9" from an early bronco (66-77) ????? What about the Dana 44 from the front???/ I just happen to have a set beside my shop now..If it wont be too much of a PITA, I might just look at this closer....
 
Well.....

The drawback to the Front EB 44 is that it has 297 joints. The 9 is not 31spline but 28spline. But there width is awsome. I think Farmer Matt used a set from a EB.
 
Ok, I may have spoken too soon about this. The one I've heard being a direct bolt in came out of a '78-'79 fullsize Bronco. I've heard this first hand from several guys who've done this swap, so I don't think its SPBOI; I think it depends on the housing.
I have a 79 bronco housing sitting in the garage. I ran down and measured the spring pads. 44" on center. It would bolt in. But is the pinion angle correct or close enough to shim? I don't know. The earlier bronco's are about 2" narrower than the XJ axle. 58" overall.
The 9" is an awesome axle. The draw back is the low pinion as others said, but I would go with it.
 
Ghost said:
The drawback to the Front EB 44 is that it has 297 joints. The 9 is not 31spline but 28spline. But there width is awsome. I think Farmer Matt used a set from a EB.

Ghost, the EB44 has 260x joints/shafts not the larger 297x/760x.
 
Yea I just saw that.....

I was in a hurry and typed that wrong. I know the EB has 260 not 297's!
 
I thought I read somewhere that the non-disconnect D30 in the XJ's had 297 joints..... Is this true ???
 
ABS ones in 89 and up or so did.....

And then in 95 or so they went to 297 joints for all the xj fronts.
 
What are recomended tire sizes when running a 31spline 9"? 36... 39??

What about a FW D44 rear, are they as strong? It would have a little better ground clearance.
 
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