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Discussion Starter #1 (Edited)
Hi there,

I'm hoping some of you knowledgeable gents can help me with an ongoing issue on my UK Ariel Atom. I've had a number of failures with the standard/factory driveshafts and CV joints.

Some time ago I had a shaft shear:




Now the inner CV joint has sheared cleanly leaving the splined shaft stuck in the diff (now removed):



I want to source upgraded/stronger shafts and CV joints, but could do with help from the K20 community identifying which bits are "standard" Honda parts/dimensions, and which are specific to the Atom. I "think" that the inboard CV joint and shaft that locate into the diff/gearbox are standard Honda parts as the gearbox itself is standard Honda, so the splines must be standard Honda otherwise they would not be compatible.

The outer CV joints (mounting to the uprights with hub nut requiring 32mm socket to undo/tighten) appear to be made by GKN and have "GKN DOENA 4S41 EA 3484 A14" stamped on them. However, google has not found anything.

So, it may be that the inner and outer CV joints are standard Honda fitment, and the half shaft that goes in one side of the diff (with mounting bracket to the engine block) is standard Honda fitment, and it is just the two outer shafts that are "custom" in order to achieve the unique wheelbase length on the Atom.

To help visualise, here are some pics:

REAR OF ATOM SHOWING ENGINE ORIENTATION AND DRIVESHAFTS REMOVED:


REMOVED SHAFTS:


CLOSE UP PICS OF SHAFTS ETC:



INBOARD CV JOINT THAT SHEARED OFF:



CLOSE UP OF INBOARD CV JOINT INTERNALS:


CLOSE UP OF "HALF SHAFT" WITH SPLINE FOR MOUNTING TO DIFF:


"HALF SHAFT" MOUNTING BRACKET TO ENGINE BLOCK:


OUTBOARD CV JOINT (SPLINE GOES THROUGH UPRIGHT) AND USES HUB NUT REQUIRING 32MM SOCKET TO REMOVE/TIGHTEN:





I want to source upgraded shafts and CV joints rated to something like 500bhp which is overkill but will stop any more issues. Can anyone on here confirm using the info/pics supplied whether the outer CV joints are standard Honda fitment/spec? If they are, then maybe I could buy a set of "off the shelf" upgraded K20 driveshafts/CV joints (e.g. something like this: https://www.tegiwaimports.com/insane-driveshafts-500hp-axles-honda-integra-dc5-type-r-01-06.html, assuming they are correct spline etc) and get a local machine shop to cut/weld the actual shafts to lengthen/shorten to the correct lengths. Obviously that link doesn't include the half shaft. Alternatively, I might be able to find a company to make a whole new set up from scratch, it would just be a hell of a lot easier if I could determine if the splines etc are standard Honda.

For reference, a single outboard CV joint with driveshaft and inner CV joint from Ariel is circa £600GBP or approx $780USD so you can see why I don't want to buy any more of them!!!!!!

Thanks for reading, any help much appreciated. Happy to provide any further information required if it helps.

:)
 

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Thought I must be missing something but looking at your history on here, everything you've ever posted is similar one word garbage. What gives?
I have sent him a PM and he has 24hrs to teply.

On your topic, anything 32mm is weak. OEM Honda axles with age will be stronger than anything reman or aftermarket. The splines that matter are the insides that go into the transmission and the halfshaft. You can contact DSS or insaneshafts and just have a custom set of axles made which ideally is your best bet. There are a few atom owners here and hopefully they can share some light.
 

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There's a very good clue in this picture, just to the left of the part number.
You just need to measure the external dimensions, count the inner & outer splines & do a bit of research to find which model its from.

As for the inner joint, it looks like a normal Honda tripode joint but could be a cheaper aftermarket part.

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Definitely with the power you are making now and what we have for you next with the MR1320 MercRacing Supercharger kit. you will need stronger axles. I recommend you send a message to Drive Shaft Shop and get some strong ones made. they can build anything. You can provide them the details of the units you have and they will give you what you need.


https://www.driveshaftshop.com/
 

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Discussion Starter #6
Thanks for the replies, much appreciated.

I've been in touch with a driveshaft company over here in the UK and they are going to make me a custom set of shafts (warranted for life so if they do fail they will be replaced for free), plus stronger off the shelf CV joints. In case anyone else has this issue, the inner CV joint (going into the diff) is standard Honda splines etc. The outboard CV joints (going through uprights) are NOT Honda spec. The place I went to had a quick check whilst I was there and some off the shelf CV joints for Ford fitment match perfectly. They are going to look through their database to spec the most suitable ones. At least this means if the CV joints ever do go again I will be able to get replacements anywhere and cheaply without having to go to Ariel and pay over the odds arsehole TAX for the privilege.

Waiting for final price (depends on CV joints), but looking like two complete upgraded warranted sets (two shafts, four CV joints) will cost just over what Ariel charge for one side :facepalm:

Thanks again :)
 

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Definitely with the power you are making now and what we have for you next with the MR1320 MercRacing Supercharger kit. you will need stronger axles. I recommend you send a message to Drive Shaft Shop and get some strong ones made. they can build anything. You can provide them the details of the units you have and they will give you what you need.


https://www.driveshaftshop.com/
Thanks for the link!
 

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Hi guys,

I am a new member here. I found this thread after suffering a similar failure.

My atom’s outer CV failed between the threaded and splined section with what appears to be signs of manufacturing marks round the outside of the fracture and tell tale signs of pulled threads indicative of over tightning.

All in all it left me with a feeling that i dont want to refit similar items, given the nature of the failure leads to an extremely hazardous condition and is realistically lethal.

Cutting to the chase CrustyGo, where did you get your replacements shafts as im after a set too!!

Kind Regards and thanks in advance !

Atomic Flyer
 

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Could you ask Ariel what their outers are from? Or even what rear hubs are used. From there, you can determine what axles you can use.
Inners are going to be for a Honda fitment. Whether you have some shop make you some custom inners, it'll have to fit the Honda spline pattern.
Outers are different. Driveshaft Shop provides their own hubs and bearings to use with their driveshafts for custom applications. I imagine Ariel uses some common hub/bearing to keep costs down, so you just got to find out what that is.

Axles are going to be a wear item and you'll likely break a few over the course of car ownership. Just plan for the cost of replacement.
 

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Discussion Starter #11
Hi guys,

I am a new member here. I found this thread after suffering a similar failure.

My atom’s outer CV failed between the threaded and splined section with what appears to be signs of manufacturing marks round the outside of the fracture and tell tale signs of pulled threads indicative of over tightning.

All in all it left me with a feeling that i dont want to refit similar items, given the nature of the failure leads to an extremely hazardous condition and is realistically lethal.

Cutting to the chase CrustyGo, where did you get your replacements shafts as im after a set too!!

Kind Regards and thanks in advance !

Atomic Flyer
Hi mate, I've sent you a PM :)
 

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Discussion Starter #12
Could you ask Ariel what their outers are from? Or even what rear hubs are used. From there, you can determine what axles you can use.
Inners are going to be for a Honda fitment. Whether you have some shop make you some custom inners, it'll have to fit the Honda spline pattern.
Outers are different. Driveshaft Shop provides their own hubs and bearings to use with their driveshafts for custom applications. I imagine Ariel uses some common hub/bearing to keep costs down, so you just got to find out what that is.

Axles are going to be a wear item and you'll likely break a few over the course of car ownership. Just plan for the cost of replacement.
Ariel won't reveal anything like that, they just want you to fork out £600GBP to them for a new complete driveshaft every time you get a failure.

What I can tell you is the outer CV joints aren't Honda fitment

I have to disagree about axles being a "wear" item, especially on a circa 600kg vehicle supposedly designed for track use.
 

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I have to disagree about axles being a "wear" item, especially on a circa 600kg vehicle supposedly designed for track use.
I mean, you can disagree all you want, but that's not going to change the fact that axles are a wear item.

If Ariel UK won't share the hub origin, maybe try Ariel USA? They might be more transparent. Last ditch effort might be to measure the hub bore, spline count, and try to match it up.
 

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Discussion Starter #14
I mean, you can disagree all you want, but that's not going to change the fact that axles are a wear item.
Brake pads/tyres/rod ends are "wear" items which I expect to regularly replace during use. A solid steel bar (axle) is not the same and I do not expect them to keep breaking through normal use. If you're happy to consider a standard axle on a standard car to be a "wear" item and happy to keep replacing at stupid cost then good luck to you.

If Ariel UK won't share the hub origin, maybe try Ariel USA? They might be more transparent. Last ditch effort might be to measure the hub bore, spline count, and try to match it up.
Read the thread properly, I went with upgraded axles/cv joints from a custom fabricator so I no longer have to get my pants pulled down by Ariel.
 

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A solid steel bar (axle) is not the same and I do not expect them to keep breaking through normal use. If you're happy to consider a standard axle on a standard car to be a "wear" item and happy to keep replacing at stupid cost then good luck to you.
I see you're getting mad, despite being confused. I'm sorry your confusion is creating anger. But, CV axles are a wear item, especially on a track vehicle. The grease, the boots, the bearings that all make up a CV axle will wear and do have replacement schedules, even uprated versions.

Do you think endurance cars are using last season CV joints? What about sprint cars? How about top tier top attack cars? They'll replace axles as a regular preventative maintenance item.
Add slicks and suddenly the axles become more likely to break.
 

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I'm neither mad nor confused. You stated that an axle, which is a solid steel bar, is a "wear" item. I simply disagree. A solid steel bar (that is specced correctly for the intended application) should not snap through normal use. This has no relation to grease or boots splitting, all the problems I have encountered involve shearing of solid steel components, whether it be the axle itself or the splined shaft going through the upright. For the record, one of my multiple failures occurred pulling out of a parking space. If you class a solid steel bar as a "wear" item and are happy to regularly replace them due to breakages on your vehicle then that's entirely up to you.

I note you are now mentioning endurance cars/sprint cars/"top tier attack" cars, why not mention a space shuttle for all the relevance it has to a standard production vehicle. If I had a "top tier attack" car (with associated budget and running costs) spending all it's time driven at the limit and beyond then of course certain components would be "lifed" and replacements scheduled in terms of hours used in "top tier" competition. But I don't have one of them, I have a standard production car which is aimed at road/track use and as such should have components designed for the intended use. I don't run slicks either despite you mentioning them.

Personally, I don't think you should ever be replacing axles/CV joints more frequently then brake pads, but we are all different and entitled to our own opinions so best of luck with yours. I don't feel there is any point continuing to argue over this as its akin to entering the Special Olympics - even if you win you are still a retard.
 

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I'm neither mad nor confused. You stated that an axle, which is a solid steel bar, is a "wear" item. I simply disagree.
Again, you can disagree, but you're still wrong.

Another thing that is a wear item, wheels. Especially on a track vehicle.

If you class a solid steel bar as a "wear" item and are happy to regularly replace them due to breakages on your vehicle then that's entirely up to you.
Yes, a steel bar that is seeing a fair amount of torque on a constant basis, including track usage, is going to be a wear item.


why not mention a space shuttle for all the relevance it has to a standard production vehicle.
Does the space shuttle use CV joints? Is your ultra low production Ariel that's built in a shed, now considered a "standard production vehicle"? There's little that is "standard" on the Ariel. Even the starting process is ridiculous. My Noble is closer to being a "standard production vehicle" than an Ariel, and it's far from being a "standard production vehicle". Are you trying to equate the same level of reliability and durability of your Ariel to say, a Mondeo or Golf, just because it's fitted with a Honda drivetrain?

Personally, I don't think you should ever be replacing axles/CV joints more frequently then brake pads
Oh, I agree, but you got confused thinking CV axles aren't a wear item, when they clearly are.
Breaking them frequently (ie. monthly, semi-annually) without doing clutch-dump launches all the time, then it would suggest a larger issue, such as component design flaw, incorrectly installed, etc. And as you rightly suggested, best to move to an uprated unit. But, even then, expect to have a replacement schedule.
 

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So I finally got round to taking mine apart.

It appears that the failure was not only the driveshaft but the Drive flange as well !!

I think that in my case the driveshaft was not the only thing to blame here. I suspect the hub bearing must have had some play in it, that translated additional stress to the drive flange and shaft tip resulting in such a catastrophic failure.

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IMG_5840.jpeg
 

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The one pictured above is an OEM Ford GKN manufactured joint, it should even have the Ford part number stamped into it so not to hard to work out what vehicle it originally from.
 

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So I finally got round to taking mine apart.

It appears that the failure was not only the driveshaft but the Drive flange as well !!

I think that in my case the driveshaft was not the only thing to blame here. I suspect the hub bearing must have had some play in it, that translated additional stress to the drive flange and shaft tip resulting in such a catastrophic failure.
Wow, that's an impressive break. Did the wheel come off too or was it saved by the brakes?
 
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