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FE Power Forums => Non-FE Discussion Forum => Topic started by: bsprowl on September 11, 2024, 07:28:33 PM

Title: Axle spline count
Post by: bsprowl on September 11, 2024, 07:28:33 PM
I've always wondered why the axle spine is often a number that does not divide evenly into 360 (degrees).  Ford uses 31 splines and after market offers 35 spines. 

It seems like it would be a real pain to set the machining equipment for 31 splines versus 30 or 35 splines versus 36. 

I've just bought a small mill and small lathe and have started looking into how to use them.  As I have no idea where to start, I'd thought I try to get this question answered as the answer may how me as I learn.
Title: Re: Axle spline count
Post by: gregb on September 12, 2024, 08:48:09 AM
Some have an even number, just not the Ford 9 inch......
Title: Re: Axle spline count
Post by: galaxiex on September 12, 2024, 06:20:30 PM
I've always wondered why the axle spine is often a number that does not divide evenly into 360 (degrees).  Ford uses 31 splines and after market offers 35 spines. 

It seems like it would be a real pain to set the machining equipment for 31 splines versus 30 or 35 splines versus 36. 

I've just bought a small mill and small lathe and have started looking into how to use them.  As I have no idea where to start, I'd thought I try to get this question answered as the answer may how me as I learn.


This video is about machining gears with different (odd number) teeth, but the process is "sorta" the same for splines.


Actually, I'm not sure it's the same for splines..... I'm not a machinist....
but I find this stuff interesting, and he explains it pretty good, I think....

https://www.youtube.com/watch?v=qVN2jrn4Kuo (https://www.youtube.com/watch?v=qVN2jrn4Kuo)
Title: Re: Axle spline count
Post by: FrozenMerc on September 13, 2024, 12:02:26 PM
When I previously worked for a power sports manufacturer, we would have tooling for only a couple of different spline profiles in an effort in minimize cost and increase commonality.  The spline profile stayed the same regardless of shaft diameter.  So the spline count was strictly a result of how the profile fit onto a particular shaft diameter.  I.E. a 1" shaft may have 20 splines, and a 1.25" shaft may have 25. It had nothing to do with dividing 360 degs by an even number.  I can't say if that was the rational behind Ford's design of axle splines, but I have been in engineering long enough to know we generally all think alike. 
Title: Re: Axle spline count
Post by: 427mach1 on September 13, 2024, 06:09:52 PM
Some have an even number, just not the Ford 9 inch......

What about the 28-spline axles that came with some 9 inch rear ends?
Title: Re: Axle spline count
Post by: badcatt on September 13, 2024, 06:12:52 PM
Some have an even number, just not the Ford 9 inch......

What about the 28-spline axles that came with some 9 inch rear ends?
Most. Only performance and some H/D axles got 31 spline axles.
Title: Re: Axle spline count
Post by: hbstang on September 14, 2024, 02:20:20 PM
i had a car that had 44 spline summers brothers spool and axles from the 80s.huge axles.the most common big axles are 40 spline now.some factory cars had 28,and 30 spline as well.
i think the spline count can influence the axle shaft diameter so more splines may not fit most rear ends or center sections.