lengel's TIII Omni GLH progress (used to be spirit r/t)

[acannell]

Well went to the track tonight. First pass was on low boost, and went a 12.0. 2nd pass snapped a drive side axle. . So back to the drawing board. I think these may have been too hard. I also took notice when I took the axle nut off it was loose and the wheel bearing had a ton of play in it. I sure this did not help things.

Par for the course for axle R&D, at least there are several things on the table that could be altered for the next round. It is an amazing thing you've done by having custom axles made.

-I am pretty sure axle shafts should not be through-hardened. The core needs to be tough but not brittle. The surface needs to be hardened to reduce spline wear and possibly for other reasons.
EDIT: That is probably not true. I think there are axle shafts that are through hardened, but possibly rarer.

-The splines are almost certainly involute. I dont think this can be ignored, but I could be wrong. After all, the splines didn't shear off. But putting the forces where they need to be may be effecting how the stress concentrates at the risers.
-I know this wont be popular, but perhaps a radical change in geometry would go much further to reduce the stress risers, since thats where the failures are occuring, versus breaking in the middle of the shaft due to exceeding tensile strength.

EDIT: One more thing, were the splines ground and/or polished? Might be a good idea to make them as smooth as possible to reduce crack formation possibilities.

Yes...this would (ducks) mean reducing shaft diameter so you can neck up at the splines. (see pic below) I believe this diagram is from a Carroll Smith book.

Check out this very good article about axle shafts, not professional or as good as an industry standard book from the library, but probably the best "write up" short of that

http://www.pirate4x4.com/tech/billav...0/index1b.html

[acannell]

On second thought..I think our axles are already diameter-reduced after the splines.

Maybe the axles you had made were over-hardened and way too brittle? Was the hardness tested?

Is it possible there is something happening in your suspension/hub that is tweaking the axle sideways and bending it, and thats having a major effect on breaking it?

I wonder if the torques can line up so the hub splines axis and the axle splines axis are significantly non-parallel, multiplying the forces in the stress risers alot? Could wheel bearings effect that relationship?

[2.216VTurbo]

We demand a metallurgical failure analysis by a qualified lab! Is it a spiral shaped grain failure or side loaded and peeled off from one side? I took a metallurgy class in college a million years ago and the instructor was a genius at figuring out failures. Stratified layer of the metal or surface notch failure, he could nail it every time. That was a fun class, we used to stretch/bend/sheer load/torque load metal pieces until they failed sometimes spectacularly! With the new info of the shattered Tri-Pods do you think they may have failed FIRST and taken out the axle?

[lengel]

Well when I found out that the tripod joint failed I decided I'm done trying to make these work. I don't really want to break a axle every time I go to the track till I happen to get it right. I talked to a company last week and they are going to be building me a set of axles with Porsche style joints inner and outer. I will be sending them srt4 inners, knuckle, wheel bearing, and some other parts this Monday. They also offer a no questions asked 100% replacement warranty of there axles!

Adam

[turbovanman²]

Neato but I hate to ask how much, lol.

[GLHS320]

Well when I found out that the tripod joint failed I decided I'm done trying to make these work. I don't really want to break a axle every time I go to the track till I happen to get it right. I talked to a company last week and they are going to be building me a set of axles with Porsche style joints inner and outer. I will be sending them srt4 inners, knuckle, wheel bearing, and some other parts this Monday. They also offer a no questions asked 100% replacement warranty of there axles!

Adam

Does it come with a lifetime 100% replacement warranty? Can you share the name of the company making them.

[turboshad]

Well now I'm interested (not that I wasn't before. ). With the cost of shipping and my lack of trust in DSS axles I had always planned to make my own. I really wanted to use the 911 ends with all the options out there but wasn't sure how they would fit so I'm excited to see what they come up with. I'll be curious to see what they use for the outer as I didn't think the 911 stuff had enough range of motion unless you cut back your steering angle.

[lengel]

Well now I'm interested (not that I wasn't before. ). With the cost of shipping and my lack of trust in DSS axles I had always planned to make my own. I really wanted to use the 911 ends with all the options out there but wasn't sure how they would fit so I'm excited to see what they come up with. I'll be curious to see what they use for the outer as I didn't think the 911 stuff had enough range of motion unless you cut back your steering angle.

Yeah I refuse to give DSS anymore of my money. I payed $1000 for there level5 axles and all you get is stock outers and inners with a 300m bars! Im done with them. To be honest this is just in the beginning stages so they may not work on the outer. I will know more once they get the parts. The outer joint has a max 40deg. I have to take a look how much angle is needed for are steering. Do you happen to know?

[Reaper1]

This is the direction I really thought this would end up going anyway.

[turboshad]

When I measured for my control arms I got 27.25deg on the inside radius which should be the sharpest. Then you need to add which ever is greater of the suspension travel and chuck it into some Cartesian coordinates to get the max CV angle. Do you know what outers they are looking at that can handle 40deg? Are the splines larger on the porche stuff? I would imagine so. I also like being able to remove the axle without taking the spline end out of the tranny. Sure makes track side repairs nicer.

[OmniLuvr]

I thought the higher performance Porsche cv's were the "930" cv's, not sure if it matters? but im pretty sure that's what we used on all the high horsepower long travel 100k dune buggies we used to build.

Yeah I refuse to give DSS anymore of my money. I payed $1000 for there level5 axles and all you get is stock outers and inners with a 300m bars

wow, that's kind of lame... but what part of there shafts were you breaking?

anyways, I think the Porsche cv's will be frickin awesome!!!

[turboshad]

You are right OmniLuvr, I didn't take the time to look again and just thought it was the 911 stuff. It's been a while since I've looked into it and my memory is nothing I brag about. And never mind on the outers Adam, I think I found who you are using and I see the 40deg parts. Looks like they have a great selection of parts.

[bakes]

has anyone tried MOD the Dakota or Ram 1500 front cv stuff to fit ????

[lengel]

Neato but I hate to ask how much, lol.

They they gave me a ball park of $2200 for the whole system. I thought this was every reasonable considering this is all one off stuff for them.

Does it come with a lifetime 100% replacement warranty? Can you share the name of the company making them.

Yes Lifetime 100% replacement. Company is RCV performance

When I measured for my control arms I got 27.25deg on the inside radius which should be the sharpest. Then you need to add which ever is greater of the suspension travel and chuck it into some Cartesian coordinates to get the max CV angle. Do you know what outers they are looking at that can handle 40deg? Are the splines larger on the porche stuff? I would imagine so. I also like being able to remove the axle without taking the spline end out of the tranny. Sure makes track side repairs nicer.

Yeah they will be using there 30 spline 930 joint, and they use a 1.250 splined shaft. Where as the stock joints only uses a 1" splined shaft.

I thought the higher performance Porsche cv's were the "930" cv's, not sure if it matters? but im pretty sure that's what we used on all the high horsepower long travel 100k dune buggies we used to build.



wow, that's kind of lame... but what part of there shafts were you breaking?

anyways, I think the Porsche cv's will be frickin awesome!!!

I was broke the end off inside the trans with the DSS axles. This is why in don't see any value in there axles since the use the stock ends. With the srt4 diff I broke the cross bar that I made, and the tripod.

has anyone tried MOD the Dakota or Ram 1500 front cv stuff to fit ????

I never looked into them. Is there any features on them that would make them better or stronger?

[bakes]

they have larger tripods and thicker shafts for stornger shock load if you think about it a 4.7l, 5.9 or57 hemi 5 or 6spd in 4 low with 28-33 tall tires dropping the clutch in a thick mud hole they have to stand up

[Dan15]

Hey lengel your inbox is full..

[lengel]

Hey lengel your inbox is full..

Sorry! Cleared some out now.

[BadAssPerformance]

I was broke the end off inside the trans with the DSS axles. This is why in don't see any value in there axles since the use the stock ends. With the srt4 diff I broke the cross bar that I made, and the tripod.

The DSS ends are stock size but 4340 material.

Did the tripod break first or the shaft at the tripod?

[lengel]

The DSS ends are stock size but 4340 material.

Did the tripod break first or the shaft at the tripod?

Not from what they told me. I would verify that with them, and have them prove that they are using 4340 on the ends.

I really think the tripod broke first then the shaft at the outer joint, I think all of it happened on the same launch.

[lengel]

Rcv told me it would take 8 weeks to build me a set of axles with mounting flanges, and only 2 week if I did my own flanges. I really want to make SDAC so this is what I came with for flanges. Thank you mr. Slowe for welding the up for me today!