Outer Limits 4x4 Board

Hi all
I have a 10 spline rear air locker in a 91 rangie
and want to upgrade the axels
Can i change my side gears to 24spline or need new locker
cheers

Hi,

http://dedq15.mindfly.com/uploads/PDF/o ... s/5-14.pdf


you will find all the info here but it's rarly cost effective to do this, we usually just recommend selling the 10 spline and buying a new 24 spline one,

Jacmac will rebroach to 24 spline, but its $300

Or just buy 10 spline hytough axles

Is it an off the shelf kit or special order
As for cost if i sold my ten spline id be down about 400 if i could sell it

Are th 10 spline hituffs that much weaker
Im running 33s but try to go easy these days

yarrum wrote:Are th 10 spline hituffs that much weaker
Im running 33s but try to go easy these days

I ran them in one of my old rangies, with 33's and a mate had some in the back of his with 35's, seem good enough

Cheers
Will look into it

yarrum wrote:Are th 10 spline hituffs that much weaker
Im running 33s but try to go easy these days

10 spline Maxi breaks at 5635Nm
24 spline Maxi breaks at 7835Nm

Slunnie wrote:

yarrum wrote:Are th 10 spline hituffs that much weaker
Im running 33s but try to go easy these days

10 spline Maxi breaks at 5635Nm
24 spline Maxi breaks at 7835Nm

Standard 10 spline breaks at 45Nm

cloughy wrote:

Slunnie wrote:

yarrum wrote:Are th 10 spline hituffs that much weaker
Im running 33s but try to go easy these days

10 spline Maxi breaks at 5635Nm
24 spline Maxi breaks at 7835Nm

Standard 10 spline breaks at 45Nm

what does the standard 24spline break at?

GRIMACE wrote:

cloughy wrote:

Slunnie wrote:

yarrum wrote:Are th 10 spline hituffs that much weaker
Im running 33s but try to go easy these days

10 spline Maxi breaks at 5635Nm
24 spline Maxi breaks at 7835Nm

Standard 10 spline breaks at 45Nm

what does the standard 24spline break at?

About the same - somewhere on the ashcroft site is a test to prove it...

Rover Bible

10 spline Maxi (Hytuff) breaks at 4160 ft/lb
24 spline Maxi (Hytuff) breaks at 5780 ft/lb


Ashcroft Transmissions

10 Spline OE (Cheddar) axle breaks at 3270 ft/lb
24 Spline OE (Cheddar) axle breaks at 3358ft/lb
Ashcroft 24 spline (4340) axle breaks at 7468 ft/lb


Out of interest, here are the front axles also from Ashcroft Transmissions

24/32 Spline OE (Cheddar) axle breaks at 3447 ft/lb
10/32 Spline OE (Cheddar) axle breaks at 3712 ft/lb
Ashcroft 24/23 (4340) axle breaks at 6231 ft/lb



Note that these are outright figures and comment nothing on the axles ability to absorb impact through flex etc.

Note that Maxi values are now in ft/lb for comparison purposes.

To add further commentary to this, the data really surprises me as Hytuff is a higher tensile alloy in comparison to 4340 or Cheddar cheese, but Ashcroft Transmission axles have a higher torque value. There are a number of variables, probably the most significant being the heat treatment process, though the same applies to both 4340 and Hytuff.

I also hypothesis that the 10/32 front axle was favourable over the 24/32 axle due to greater stress concentrations at the CV end.

Dave,i just had a look at your test breakage results.

did your 24slpine short rear only twist 246 degrees before breaking?

i know that MD axles could have been heat treated differently, to get a higher tensile strength(i hope thats the correct termanology) but that reduces the ductile properties.

looking at the specs of hytuf v 4340 there is no reason why a hytuf axle couldnt achive the same or better results on a test rig......... but thats not the real world. it does give some insite though.

long term shock loading will determine the life of an axle.

Serg

Thats a big differance from 10 spline maxi 4160
to the 24s 5780
What would my stock stage1 SALS rear be

Slunnie wrote:
To add further commentary to this, the data really surprises me as Hytuff is a higher tensile alloy in comparison to 4340 or Cheddar cheese, but Ashcroft Transmission axles have a higher torque value. There are a number of variables, probably the most significant being the heat treatment process, though the same applies to both 4340 and Hytuff.

.

Probably more to do with different test beds

cloughy wrote:

Slunnie wrote:
To add further commentary to this, the data really surprises me as Hytuff is a higher tensile alloy in comparison to 4340 or Cheddar cheese, but Ashcroft Transmission axles have a higher torque value. There are a number of variables, probably the most significant being the heat treatment process, though the same applies to both 4340 and Hytuff.

.

Probably more to do with different test beds

I think the difference is that the MD values are calculated (conservatively by Mal), vs the figures that Dave measured.

So the MD values are based on diameters and the strength Mal expected from his hardening process (he apparently treated them to have optimum satigue life, but possibly slightly lower ultimate strength).

Yarrum - check the figures above for stock 24 spline (your sals axles). However IME, Series 3/county vintage 24 spline stuff is slightly better material than later stuff.

uninformed wrote:did your 24slpine short rear only twist 246 degrees before breaking?

yes, more than I thought for a short shaft but the important twist figure is the 115 deg of elasticity, stock was 60 deg,

uninformed wrote: looking at the specs of hytuf v 4340 there is no reason why a hytuf axle couldnt achive the same or better results on a test rig......... but thats not the real world. it does give some insite though.

I agree Hytuf is a very good material, it's not 'real world' but it's more than just an insight, it's fact.

uninformed wrote: long term shock loading will determine the life of an axle.

I agree it's an important factor but not a determining factor, ie a stock weak brand new shaft may fail first time out due to UTS not from shock loading or fatigue.

cloughy wrote: Probably more to do with different test beds

Yes two different test beds will always give different results but one rig will give good comparison data.

isuzurover wrote:I think the difference is that the MD values are calculated (conservatively by Mal), vs the figures that Dave measured.

conservatively ? so you could say these figures are 'maxi theory vs ashcroft fact'

isuzurover wrote:So the MD values are based on diameters and the strength Mal expected from his hardening process (he apparently treated them to have optimum satigue life, but possibly slightly lower ultimate strength).

I want to point out I am not bashing Maxi products, Hytuff or Mal he is a good engineer who made good products but I can't help but think this is a no win situation, ie if our UTS torque figure was lower we would all agree Maxi was stronger but as ours have a higher UTS they are not stronger but will fail from fatigue life!!!

I am not saying 'ours are better' , I really don't think theres anything in it, both are very good products.

i guess its just that since MD have such a great long term reputation. Others have come along and made claims and sure they look good on paper but dont make that next big step up.

for me its just hard to get my head around 2 axles that are the same spline and probably very similar design..... made from different materials. its a big difference between 5780ft/lb and 7468 ft/lb especially when the larger figure is coming from a material that is considered not as good as the lower.

yes i know heat treating is a very big factor, and thats why i said that the hytuf axles could be treated to bring up there UTS.

saying a stock axle will break first time out due to UTS not shock loading or fatigue is a moot point as its not really in the same leauge as 4340 or hytuf.

dave have you broken any maxidive axles on your test rig?


as far as 'maxi theroy' is concerend, im willing to take his calcs with confedence....also your test results. do you have any other fomulas that would result in a different figure for MD's hytuf axle data?

Serg

Dave - I am certainly not knocking your products.

I am not 100% sure if Mal ever tested the strengths of his axles (he certainly never showed me a test rig of any kind when I was there). However the reason I said conservative, is that Mal quoted a UTS of 1550MPa for his axles. However some manufacturers quote figures up to 1655MPa for the same steel HY-TUFF/AMS6418. I remember John (Bush65) saying something about 1500ish MPA for this steel being some special point on some izod(?) curve????

CTM (one of the leading US axle manufacturers) make their axles from 300m, but use HY-TUFF/AMS6418 when they can't get 300m.

Here is some info I compiled and posted a long time ago... Some of it is probably wrong:
http://www.outerlimits4x4.com/phpBB2/ftopic31879.php

The figures that Mal published were calculation of torsional strength using the polar moment of inertia of the shaft and the material properties. It was meant to compare the different shafts/materials.

A test rig that applies a steadily increasing torque until the shaft breaks is another way to compare axles.

You have to understand what either of these methods demonstrate and the implications to real world abuse of axles and failure criteria. There is much more involved in axle failure than ultimate torsional strength.

Hy-tuff mechanical properties are superior to 4340 for this application. 300M (4340 modified) is better again.

Tempering is the heat treatment process that is applied after material is quenched. Quenching (from the appropriate temperature) produces high strength, but tempering is required to increase the toughness (at the expense of some tensile strength).

Parts subjected to shock loads need good impact strength. Izod impact energy is a usual measure to evaluate impact strength. Hy-tuff exhibits very high izod properties combined with high tensile strength, at a particular tempering temperature.

I have no idea what heat treatment temperatures were used or the resulting material properties for Maxi-drive axles.

Features such a splines cause very high local stresses. These are called stress raisers. Stress raisers don't have much influence on the static strength - such as would be involved when an axle is loaded to destruction in a test rig. Stress raisers only create high stresses in a very small region. In a static test, the load is redistributed to lower stressed material when the stress in the small region exceeds the yield strength.

The critical problem with stress raisers is great reduction in the fatigue strength. Parts that are subjected to repeated (cyclic) fluctuating loads can fail (fatigue) under loads much less than their static strength.

Shock loads introduce different problems again. Stress raisers are still critical, but the resilience of the part is important in this case. A shaft that can absorb more strain energy will perform better. The reduced strain energy capacity is the main reason short side axles break more frequently than long side axles. Waisted axles have more resilience and can absorb more impact energy (as strain energy), than non-waisted axles.

Edit: Diameter has a very big influence on shaft strength. So I don't use rover axles any more (except the 24 spline maxi axles in my disco which is never pushed hard enough to break them).

sorry to bring this back from the dead but does anyone have the figures for 30 spline Toyota type shafts?

Yorker wrote:sorry to bring this back from the dead but does anyone have the figures for 30 spline Toyota type shafts?

From the longfield website.

1st 2 results are:
Standard toyota CV (27/30 spline) - failed at bell
Welded/heat treated toyota CV (27/30 spline) - failed at 30spl stub shaft


EDIT - INTERESTINGLY... The CS area of a 1.31" toyota shaft is about 5% greater than a 24spl rover shaft. If you increase Dave's value (7468) by 5%, you get about 7900 - so in the ballpark for the 4340 stub failure.

Well back to the original question how did ya go changing the side gears from 10 to 24 spline ???

The arb web site has this as a kit to change them over im still waiting on my local ARB guy to get back to me on weather the parts are still available and price as i have 2 10 spline ARB's and would like to swap em over to 24 spline ....

Nothin done as yet
Will try arb for kit before xmas if cashed up
If not prob give hi tuff 10splines a go

lokka wrote:Well back to the original question how did ya go changing the side gears from 10 to 24 spline ???

The arb web site has this as a kit to change them over im still waiting on my local ARB guy to get back to me on weather the parts are still available and price as i have 2 10 spline ARB's and would like to swap em over to 24 spline ....

The side gears alone are US$125 each (probably $200 each in AU???). That is without all the other poarts you need.

So the $300 that McNamara charge to broach the gears sounds like a better deal.

ISUZUROVER wrote:

lokka wrote:Well back to the original question how did ya go changing the side gears from 10 to 24 spline ???

The arb web site has this as a kit to change them over im still waiting on my local ARB guy to get back to me on weather the parts are still available and price as i have 2 10 spline ARB's and would like to swap em over to 24 spline ....

The side gears alone are US$125 each (probably $200 each in AU???). That is without all the other poarts you need.

So the $300 that McNamara charge to broach the gears sounds like a better deal.

I agree. And despite all of the myth and rumour surrounding dealing with Jeff, he is actually quite good to speak with. At least that's how I found him.

But when you add up the broaching $600, 24 spline HYTUFF axels ~$1600 front and rear and disassembling and reassembling the diffs, its gets quite exey...and you still have the weak stock Rover ring and pinion.

But when you look at a Toy conversion: Diffs ~$150 each, McNamara rear axels ~$660, McNamara front axels ~$660, Longfield CVs ~$500, RoverTracks Drive Flanges ~$200, plus lockers ~$1500 and fitting it all
...the 10 to 24 spline conversion sounds quite good.

[/quote]

But when you look at a Toy conversion: Diffs ~$150 each, McNamara rear axels ~$660, McNamara front axels ~$660, Longfield CVs ~$500, RoverTracks Drive Flanges ~$200, plus lockers ~$1500 and fitting it all
...the 10 to 24 spline conversion sounds quite good.[/quote]

where do you get longfileds for 500? are they 27 spline or 30?

Serg

ISUZUROVER wrote:

lokka wrote:Well back to the original question how did ya go changing the side gears from 10 to 24 spline ???

The arb web site has this as a kit to change them over im still waiting on my local ARB guy to get back to me on weather the parts are still available and price as i have 2 10 spline ARB's and would like to swap em over to 24 spline ....

The side gears alone are US$125 each (probably $200 each in AU???). That is without all the other poarts you need.

So the $300 that McNamara charge to broach the gears sounds like a better deal.

I thought all the bits were made here in AU not the US il have to give my arb mate another call and find out what the go is as 125 US each sounds stupid ....

As for rover CW+P being weak pegging fixes that tho having the diff set right in the first place helps alot too ...

uninformed wrote:

But when you look at a Toy conversion: Diffs ~$150 each, McNamara rear axels ~$660, McNamara front axels ~$660, Longfield CVs ~$500, RoverTracks Drive Flanges ~$200, plus lockers ~$1500 and fitting it all
...the 10 to 24 spline conversion sounds quite good.[/quote]

where do you get longfileds for 500? are they 27 spline or 30?

Serg[/quote]

That's how much mine were from Longfields thru RoverTracks...but the Aussie dollar was 93cents at the time.

And they are 30 spline.