Why are 31 Spline Axles Better than 28 Spline Axles?
#1
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I'm in the market for a new rear end and while doing some research and over the years I've heard/read that a higher spline axle is better than a lower spline, why is that?
To me it would seem that a 28 spline would be stronger than a 31 spline since there would be more "meat" in between the splines.
Could someone please explain in detail why a higher spline axle (31) is better than a lower spline (28).
Bill
To me it would seem that a 28 spline would be stronger than a 31 spline since there would be more "meat" in between the splines.
Could someone please explain in detail why a higher spline axle (31) is better than a lower spline (28).
Bill
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2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
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#7
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Well Bill, it is mostly like what has already been stated for replies.
In summation... its overall diameter does lend to greater surface area. The greater the surface area, the greater the area in which to spread the mecahnical load. As for spline count... it really depends on the spline shape and pressure angle, not merely the number of. More splines doesnt necessarily mean 'better' or 'stronger'. And last but not least by any means... the material it is comprised of. You can have a 28 spline 35% stronger than that of a 31 spline just by changing materials. But, material cost becomes the issue from here...
In most cases the larger the better, specifically with like materials. But, better materials in like sizes can do more for you... it just costs more.
In summation... its overall diameter does lend to greater surface area. The greater the surface area, the greater the area in which to spread the mecahnical load. As for spline count... it really depends on the spline shape and pressure angle, not merely the number of. More splines doesnt necessarily mean 'better' or 'stronger'. And last but not least by any means... the material it is comprised of. You can have a 28 spline 35% stronger than that of a 31 spline just by changing materials. But, material cost becomes the issue from here...
In most cases the larger the better, specifically with like materials. But, better materials in like sizes can do more for you... it just costs more.
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keep in mind, theres a set "standard" for axles.
take the ford 9" for example.
theres the standard 28 spline axle. this is what came in ford cars for years.
theres the standard 31 spline axle. this is what came in ford trucks and HO cars..
and then theres the 35 or whatever spline ones.. this is all aftermarket, low single digit car stuff.
now the spline count is NOT the only diff between them. the physical size of the axle is diffrent. the 31 is larger then the 28.. and the 35 is just massive.
however, its MUCH easier to refer to them by their spline count. afterall, thats how we can tell if they interchange with our diff/spool/locker....
theres an obvious strength diff between a 31 spline late 60s OEM ford axle from a mustang, and a new moser 31 spline axle of the same dimentions... theres length, bolt pattern, bearing size, etc....
but for our website, 90% of us assume we're talking about aftermarket axles for an Fbody... oor we only need to know what centersection spline we need to match.. and because of that, we just refer to the spline count.
take the ford 9" for example.
theres the standard 28 spline axle. this is what came in ford cars for years.
theres the standard 31 spline axle. this is what came in ford trucks and HO cars..
and then theres the 35 or whatever spline ones.. this is all aftermarket, low single digit car stuff.
now the spline count is NOT the only diff between them. the physical size of the axle is diffrent. the 31 is larger then the 28.. and the 35 is just massive.
however, its MUCH easier to refer to them by their spline count. afterall, thats how we can tell if they interchange with our diff/spool/locker....
theres an obvious strength diff between a 31 spline late 60s OEM ford axle from a mustang, and a new moser 31 spline axle of the same dimentions... theres length, bolt pattern, bearing size, etc....
but for our website, 90% of us assume we're talking about aftermarket axles for an Fbody... oor we only need to know what centersection spline we need to match.. and because of that, we just refer to the spline count.
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Originally Posted by Revelation Z28
its wierd though how 3 more little splines would add strength to something.
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Originally Posted by mzoomora
That 3 spline is 10% more, plus the increase in diameter and the fact that it is an aftermarket axle Vs. the stock 28 spline axle. Also, you are also talking about a 9" Vs a stock 7.6. Comparing a 28 to 31 spline 9" factory axles the difference isnt nearly as great.
i know from what we have stock compared to any other rear end that we can use its like we have toothpicks in there
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Originally Posted by Revelation Z28
well i was comparing the same rear ends together. 9" 28splive vs 9" 31 spline 12 bolt vs 12 bolt.
i know from what we have stock compared to any other rear end that we can use its like we have toothpicks in there![The Jester](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_jest.gif)
i know from what we have stock compared to any other rear end that we can use its like we have toothpicks in there
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anything larger is overkill.. and theres a TON of cheap 31 spline parts out there....
theres 28 spline stuff, but not as much heavy duty racing stuff, and it costs more (simply because theres not as much of it)
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Originally Posted by MrDude_1
if you go 9", get the 31 spline.
anything larger is overkill.. and theres a TON of cheap 31 spline parts out there....
theres 28 spline stuff, but not as much heavy duty racing stuff, and it costs more (simply because theres not as much of it)
anything larger is overkill.. and theres a TON of cheap 31 spline parts out there....
theres 28 spline stuff, but not as much heavy duty racing stuff, and it costs more (simply because theres not as much of it)