Topic: 2.5L VS. D60

[FourbangerYJ]

Have any picts of the removed shaft?

No, I'll ask for some.

[FourbangerYJ]

Pretty clean break. A fair amount of twist.
It was the driver side.

[sharpxmen]

Pretty clean break. A fair amount of twist.
It was the driver side.

wow, what was that made of?

interesting that 2 areas of the shaft had behaved differently (one twisted and then snapped right at the sharp edge of the splines)

[oldjeep]

I would put the hubs back on even with cro-moly shafts.  In the video it looks like the shaft snapped because of the torque from the gearing and not a shock load.

You can shave a 14B a lot if you're willing.  They're dime a dozen and don't carry the premium like the D60 does.

Much easier to just get a D60, chop off the ends, weld on Ford big bearing ends and then use 35 spline SF shafts.   The one I built cost $500.  To weld on the big bearing ends, you do need an alignment bar and pucks - but luckily my friend has one.

I've got a 14 bolt under my streetrod, and even with a shave you would have to be running some awful big tires to get any clearance out of it.

[FourbangerYJ]

wow, what was that made of?

interesting that 2 areas of the shaft had behaved differently (one twisted and then snapped right at the sharp edge of the splines)

Not sure what material that was.
That is the nature of axles shafts. The straight part would go into the hub or drive flange in this case. Not sure how far it goes in but atleast a inch. So it can't twist. Therefore the are of the shaft that is right next to the area which is inside gets the full brunt of the twisting forces. As you can see it twisted until it couldn't take anymore then SNAP!. The higher quality shaft material will twist more before snapping.
I am not sure I understand why some shafts snap and it looks like those above. Like they where put in a chop saw. Others I have seen have twisted and broke and it looked like the broken ends were put into a pencil sharpener (sorta). I thought the higher grade material snapped clean. Not sure thou.

[Jeffy]

I've got a 14 bolt under my streetrod, and even with a shave you would have to be running some awful big tires to get any clearance out of it.

He said he wants to run 39's.

I am not sure I understand why some shafts snap and it looks like those above. Like they where put in a chop saw. Others I have seen have twisted and broke and it looked like the broken ends were put into a pencil sharpener (sorta). I thought the higher grade material snapped clean. Not sure thou.

It has to do with the construction, hardening and the force applied.  If you look at the side shot you can see the shiny edges with a dull core.  The hardening was pretty deep which aligns the molecules so you get a clean break.  The other type of break usually looks like a spear since the hardened surface breaks off the softer core material and is more of a longitudinal crack.  Kind of like peeling a banana.

[FourbangerYJ]

Here is the type of break that also occurs. I would say this is a stock axle, they seem to break this way VS. the clean cut.

[Jeffy]

Here is the type of break that also occurs. I would say this is a stock axle, they seem to break this way VS. the clean cut.

That's the longitudinal crack I mentioned.  You can see it basically peels off the ahrdened surface off the softer.  That groove that looks like someone swiped the finger in butter is the hardened surface while the chunky bits are the softer bits.

[sharpxmen]

i'm also thinking that it could have something to do with the splines in terms of if they are rolled vs machined (cut) - the ones that are cut i think would created more concentration of the force towards the sharp edge where the spline ends whereas the rolled ones would transfer the tension towards the rest of the shaft due to the way the molecules are aligned during the rolling/pressing of the splines (sorry Jeffy, stole your molecular approach) - would be interesting to find out what type of shaft it was just for future reference.

[FourbangerYJ]

Further research I first found it on Google images. It was on the JK forum. It was a front shaft. Not sure if it was a Rubi or not.

[Jeffy]

i'm also thinking that it could have something to do with the splines in terms of if they are rolled vs machined (cut) - the ones that are cut i think would created more concentration of the force towards the sharp edge where the spline ends whereas the rolled ones would transfer the tension towards the rest of the shaft due to the way the molecules are aligned during the rolling/pressing of the splines (sorry Jeffy, stole your molecular approach) - would be interesting to find out what type of shaft it was just for future reference.

Rolled Splines are stronger just like how forging is stronger then cast.  Instead of cutting splines, the ones that are rolled are denser because of the rolling process compressing material.  I don't think they get aligned until the hardening process which comes afterward.

[sharpxmen]

Rolled Splines are stronger just like how forging is stronger then cast.  Instead of cutting splines, the ones that are rolled hare denser because of the rolling process.  I don't think get get aligned until the hardening process which comes afterward.

 can't remember the exact terminology - but you're right, it's similar to rolled bar, the molecular structure is continuous whereas with the splines being cut there is an break in the structure where the material is removed

[FourbangerYJ]

UPDATE He chipped some teeth off the Detroit when the shaft broke.

[neale_rs]

This is getting worse and worse.