eliofall

What is the diameters of the major and miner of the spline for the ford 9" of 29 and 32, 35 spline count?

big gear head

9 inch Ford axles are 28 and 31 spline. There are after market 33, 35 and 40 spline axles for it.

eliofall

Ok but what I would like to know is the minimum and major diameter of the splines. Is the major diameter the same for 29 and 31? What about 35?

big gear head

No, the 28 spline axle is smaller than the 31 spline axle at the splines. As the number of slines increases so does the diameter of the axle. 40 is larger than 35 is larger than 33 is larger than 31 is larger than 28.

AlkyIROC

The physical size of the splines are the same. It's not like you have a 1-1/2" diameter shaft with 28 course splines or 40 fine splines. As mentioned above, the increase in spline numbers means an increase in shaft diameter which also means an increase in torque capacity.

The axle shafts also vary in diameter along the length. From the bearing end to the spline end, they don't all stay the same diameter. Many GM axles taper downward towards the splines then increase right at the start of the splines.

Some aftermarket axles also have different shaft sizes. I once had a set of Strange axles. The main part of the shaft was smaller than the spline area. There's no way the shaft could be shortened and resplined. My Moser axles are the same diameter as the splines so if it was economical, they could be shortened and resplined.

When you start getting into large axles with 35 and especially 40 splines, the axles start to get heavy. These axles have the option of gun drilling where they drill out most of the center of the axle to make it lighter.

Ford only offered 28 and 31 spline axles in production vehicles. I wouldn't even recommend 28 spline axles in a street car. A standard ford case can accept 33 spline axles providing you use the associated carrier (posi). When you go to 35 or 40 spline axles, you need an aftermarket case with larger 3.250" side bearings. There are some aftermarket posi's and spools that allow large axles in the smaller case but I wouldn't trust them since they need to machine down the side for the smaller bearings which leaves a lot less metal to hold everything.

eliofall

if the "physical size" is the "same" then why is it "not like you have a 1-1/2" diameter shaft"?¿?

i am in fear that i am being miss understood...

i want to shorten a set of axles that i have. i need to know the diameter of the splines and how deep the root is; that would be the major and miner diameters. so i can re-spline them and all after i cut them down.

think of splines like a thread(a screw).. say a 1/4" x20 TPI 2A 60 degree. thats something I'm sure we all have used. the outside of the thread is .2489"(+0.000/-.0081) or 1/4" that is the major diameter. if you look at the bolt, from the side, you will see the vee shape that the thread makes from the 60 degree angles make. the lowest point, that is where the vee come together, that depth is .0305"~ so that makes a diameter of 0.1876". that is the miner diameter.

so, the major and miner diameter are .248" and .187" respectively.

so again, i inquire, as i did at first; what is the major as well as the minor diameter of the splines for the ford 9" of 29 and 32 as well as the popular after market 35 count spline count.

please, beseech thee

AlkyIROC

Where did you miss all of us telling you that Ford 9" axles are 28 and 31 spline with 33, 35 and 40 being aftermarket?

Wanting to cut down an axle and have it resplined isn't exactly cheap. To do it accurately, you need some specialized machines and like I mentioned above, not all axles are large enough to be cut down for resplining. If you want the exact measurements of the shape of the splines, measure the splines from the axle you intend to cut down. OEM, Moser and Strange as well as many others use the same spline pitch. Mark Williams axles use a different pitch to the splines and are not interchangeable.

It's much cheaper and easier to buy aftermarket axles that are the correct size and spline count. If you already have aftermarket axles, it easier to send them back to the manufacturer for modifications.

AlkyIROC

http://www.markwilliams.com/axle-txt.aspx

eliofall

where did i miss it? simple. that you have told me what the counts are and that they used different bearings. and now you tell me about specialized machines, and that not all axles can be cut down and the cost there of.

while i do thankyou for your input, all your typing has not set the answer of which i seek into the open. you cover things that have little and nothing to do with what i asked.

it is much cheaper, for me, to re-spline the axles. other people this may not be the case. for those people i care not. i have my own needs, and the only thing i need is knowledge, and not your kind hearted opinion.

i thought i asked for something very simple, it seems that no one understood what i asked so i tried to explain it better for the laymen... what every you want to call your self... so here please look at the picture.
(a) MAJOR DIAMETER: The largest diameter of a screw thread; measured from the crests on external threads

(c) MINOR DIAMETER: The smaller diameter of a screw thread; measured from the roots on external threads




now please, if you do not know or still do not understand, i beg you, hold your peace. if some one happens to know the pitch of the splines i can figure out what the root depth is from that.

88gunmetalgta

iTrader: (1)

Doubtful anyone's gonna have that information. I'm assuming you have found a correct profile cutter? If you got the spline count wrong in your first post, there's a lot more numbers your gonna need to spline them yourself. I assume you have access to an induction heater?

big gear head

Yes, we understand what you are asking. We don't know the exact major and minor diameter of the axle splines. If we did we would have told you in the beginning.

Again, Ford does not have a 29 spline axle. It's 28, not 29.

Axles are case hardened and can not be cut with standard cutting tools. You need special cutters to cut splines in hardened axles. Those cutters are very expensive and break easily. It would be much cheaper for you to send your axles to Moser Engineering and have them cut them for you.

AlkyIROC

Get one of these and measure an axle. If you're asking about the pitch then you didn't read the link from Mark Williams.

eliofall

I did read the link. It says that most... it did not give a definite answer. And there are a few other problems with what it says if you try to do the arithmetic. But I am sure you already saw that too.

As for those calibers... lol. I can't find the words... alky kid, you're a prince. You really are. That name if just so fitting.

AlkyIROC

Well you can't be much of a machinist then if you don't know how to use measuring tools. Axle tolerances are really sloppy.

Call Moser and ask them for what you want to know. They build axles for a living.

88gunmetalgta

iTrader: (1)

I disagree. He must be a much better machinist than I am, because I wouldn't attempt to re-spline a set of axles

eliofall

well alky kid, again you miss understood me. you can not use a caliper to get all the way to the root of a spline and get a good reading. maybe its because the caliper i use is made by starrett and not that one you showed.

if i used some pin gauges and a caliper i could find the pitch diameter but that still doesn't tell me root.

even if i use a drop gauge/thread root tool it still wouldn't be a true reading me because of the way the splines are on the axles i have. but that is giving no thought that i haved about 2 set i dont have sitting behind my kennedy tool chest.

i read about this city in the middle east. i guess they really know how to throw a party and welcome travelers to town. anyways some family left, but this chick turned to salt when she looked back.

how about you take that cheap caliper, and the name of that city and have some fun with your self. put some maple syrup on it too.

let the bank that holds my mortgage worry about how good i am at what i do for a living. i will worry about what i do in my free time.

88gunmetalgta

iTrader: (1)

If you can't measure your existing spline accurately, how are you gonna measure the new splines you cut.

eliofall

a gaugemaker. i love those things. but i have to know what to set it to.

eliofall

see the things is the splines are so so rough that i think they are under sized. but i think i want to go with a bigger spline count. i just would like to have all the info before i decide what to do

big gear head

There are only 2 differentials available for the 35 spline axles. That's the Detroit Locker and the Wavetrac. These require the 3.250" bearing case. If you want to use 33 spline axles the only choice is a spool. When you go above 31 splines your choices are very limited.

If you are loking for strength then I would not recommend resplined axles. They are much weaker than after market axles and even unmodified stock axles. I have a broken resplined 31 spline Ford axle in my shop that I broke in my Camaro with street tires.

eliofall

the axles will only be 6" long.. well 5.5 on one side and... you get the idea. i'm making an irs 9". more of a proof of concept. the axles i have are very thick where the new splines will be so i was wanting to see all my options for reworking the axles.

putting time in to this is one thing, putting money in to something that may not work at all is another.

big gear head

I see. Go to the LS1GTO web sight and look at some of the IRS 9 inch Ford stuff that they have for the late GTO and new Camaro.

eliofall

i have seen that kit before. over priced but it does look to be using the 934cv

same thing goes for the one Boost logic makes.

there is the dutchman irs housing. i do like that one.

Heidts makes a whole rear end setup but i just dont like it. for a few reasons.

http://www.team321.com/321HotRodIRS/...odIRShome.html
i do like that setup but they are using a ford 8.8

i think i will do something alot like that but use the front spindles off an early 4x4 s10 or a late 90's grand am.

big gear head

Some pics of your progress would be great. I love to watch a good fabricator at work. I'm a toolmaker for GE aircraft engines, so I know a little about machine work, but our work is pretty specialized and I don't get a chance to do a lot of the things I would like to do. Most of the guys that I work with have never used and indexing head and don't even know what one is. I haven't used one in many years, so I would have to study it a little while before trying to use it. Good luck with your project and let us know how it's going.

Time2Fly

9" Ford 35 spline axle