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jono

how? to adapt 23 spline to 25 spline inner CV joint ?

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The inner CV joint sort of really, technically , known as DOJ (double offset joint)is the 23 spline variety to mate the 23 splines of the gearbox output stubs of:

 

std EA81 4WD

carb EA82 4WD

turbo auto EA82 4WD

 

A post on another forum got me worried enough to investigate to find it is not a simple swap of DOJ on the end of the EA81 4WD axle shaft to be able to make use of a 25 spline output stubbed gearbox.

 

I have pulled apart a 25 spline DOJ and a 23 spline DOJ - i suspect both were off 4WD

 

The 25 spline of the stub axle of the gearbox carries through to the 25 splines of the axle on the 25 spline EA82 axle assy

The 23 spline of the stub axle of the gearbox carries through to the 23 splines of the axle on the 23 spline EA81 axle assy

 

crazy as it seems, I recall the 23 spline stubs on the garbox step up to 25 splines at the crown wheel and pinion !!

 

every component of the 25 spline DOJ is that much bigger than its counterpart in the 23 spline DOJ including circlips and balls ! so nothing can be swapped/interchanged in order to do want I need to do, which what i was lead to believe - was simple- It ain't yet !

 

I need to be able to run a std 23 spline EA81 BRAT axle with std outer CV joint, but with an inner DOJ that has 25 splines to make use of a 25 spline gearbox I have been hoarding for many years.

 

I could simply ask - how do I modify the CV shafts of an EA81 to run an AWD5 manual/stick box from an EA82 - please ?

 

I recall info about doing EJ conversions and to use FWD EA81 manual, or was it auto inner DOJ cups etc to graft an EJ box to EA81 front hubs etc, there must be something I am missing, and someone on here must know, and be able to say in simplest terms..

 

An inner joint has the cups also known as outer race, to which the inner race (which has the splines) and balls and cage , fit neatly into. I cannot just take the inner race from a 23 spline and fit it to the 25 spline cage and balls.

 

Help would be appreciated :)

Edited by jono
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Hi  This is Jerry,i have 3 complete set of those axle that you are needing. Contact Shawn Watson he is a super board member and he knows how to get a hold of Marshall he makes that axle you are needing. Thanks Jerry

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Hi Jerry. Thanks for speaking up and offering contacts. You now reveal that if someone has gone to th trouble to custom make these shafts looks to be no way to mix and match ?. Sort of looks like it would be a 23 spline one end, 25 spline the other end of the axle shaft itself ?

 

Ingenious idea allowing use of standard replacement ends EA82 inners EA81 outers :)

 

Maybe that is the secret of others gone down this path I intend. I will have to go back to a shaft builder with the idea again and see if he has a resolution to the problem without custom made shafts. The other option is a crash course in box dissembly to swap in 23 spline stubs at the diff.

 

Now, wondering if a 45mm longer 25 spline EA82 axle is shortened and splined 23 at inner end ??

Edited by jono

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Our 5spds here all used 25 spline in the diff, and step down to 23 spline output for the axle stub.

 

If you split your 5spd case.....you could use a set of the stubs we got here in ours then use stock brat/brumby/ea81 axles.

 

I have a set of stubs I could ship you if you would like to go that route.

 

I have done the reverse swap to use a standard L series Dual range in a newer Legacy(liberty) car with standard legacy axles.

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Gloyale, confused self when I read that. Our 23 sopline output stubs are 25 spline inside diff too. Surely you got mpfi or turbo boxes with 25 splines on the gearbox drive stubs EA82s ??

 

Cannot use EA82 axles as they are 45mm longer.

 

I do happen to have a pair of stubs from a 23 spline box so OK on the parts need there thanks.

 

BUT, before I go down that route will not be confident unless I have factory instructions on the EA82 single range AWD box - if you have a link to that _

 

 

And, if lucky, local wrecker may still have a  FWD auto EA81 wreck to try for bits

 

Over here, many years ago a fella got a an EJ turbo box running in EA81 MY using a great mix of parts - such as FWD shafts for some reason, EJ Lib/Leg inner joint, EA81 CV joint and got the combo working. Also got a reply from a local who had similar built out of a parts mix, rather than any custom component manufacture from what I can gather.

 

Thinking about it - EJ turbo box was likely 25 spline sam as what I am hoping to do - lucky the box is not in yet and have to drive to work tomorrow :)

Edited by jono

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NEWS FLASH...

 

just taking advantage of suns hine, daylight and not too hot yet...grabbed another CV shaft to inspect.

 

It has multi rib genuine look about the inner DOJ, has larger sized spline hole to fit the 25 spline stub axles, so must be out of an L Series EA82 or Vortex

 

Inside, had to look a few times and double check - the inner race that splines onto the axle shaft has 23 spline count, not 25 as expectd due to the 25 spline to gearbox stub !

 

Thinking 23 spline axle shaft mated to 25 spline axle stub, this shaft may bell be off something different that I picled up a long while ago an E4AT out of an 89 GLTA auto 4 speed constant AWD turbo sedan RX lookalike. Rare as rocking horse stuff.

 

Genuine EA81 books indicates the FWD front axle shaft is 4mm greater between CV boot inner bands, thinking it may also reflect actual shaft length is longer by 4mm ??

 

Starts to gel something as been told and remember a similar axle conversion using FWD EA81 axle shaft, Liberty/Legacy inner DOJs to achieve similar - off on a hunt .....j

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i know that diferent manufacturers use different size and splined shafts i have a pile of old cvs and there are atleast 3 diferent sizes shapes and setups all for the front on a ea82

IMAG0030_zpse495cad7.jpg

these where both the wheel side of the axle one was factory and the other was aftermarket the shafts where diferent sizes and diferent spline count i just cant find the pic.right now

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Nice pics Ferp, thanks. And interesting to note what you say you found !!

 

 

Well, having looked high and low in the shed, looks like when i scored the shafts, did not get a matched pair so no second one to grub up a pair of trial fit shafts yet. I have noticed that the special one I want another of is smaller outer diameter than the std 25 spline DOJs, more the same if not the same OD as a 23 spline EA81 DOJ. Be curious to know if a 23 spline is small enough to be machined out to a neeto 25 spline ?

 

Word is filtering through that it is Gen1 inner DOJ fitted up to EA81 axle shafts is the go.So they must be similar if not same as my special with 25 splines for the stub and 23 for the axle inside the DOJ.

 

Never seen it spelled out in so many words and why, must be my mission in life :)

 

BUT, just by eye measure can see my special is not same length as the std 25 spliners (25 on axle stub and 25 on inner race) If the difference translates into a shorter end product it may suggest why FWD shafts are specified as they look to be 4mm longer between boots small ends

Edited by jono

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Just split the trans case and put 23 spline stubs in there.  Done.

 

Spliting the box is easy.  See my writeup on "easy front seal replacement.

 

If all you do is swap stubs....there will not really be any need to measure shims/clearances etc.....just open it.......swap stubs....and seal it back up.

 

Teh transfer gears do not need to be messed with.....the whole tailsection comes off as a unit just have to remove lock screw from shift selector shaft and rotate it out of the shift rods.

 

Do that job once.......then you will be able to run any EA81 axle you can get anywhere.

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GL Loyale is right, Modify the part you will never be replacing rather than the part that needs more servicing, otherwise every time the drive shafts need fixing it becomes a pain in the butt.

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all very well to suggest thanks Gloyale, I see yours and coxys' point entirely and was my original thinking when I pulled some 23 spline stubs from a gearbox that will never go back together again :(

 

BUT, there is a couple of reasons why I'd like to keep it a 25 spline.

 

1. as a spare for my 25 spline XT if need ever be

2. it came out of coxys' ute and neither of us know its true condition [only sat in coxys'  tray :) ] - except a fourth party supplier who test drove it, reported to me he remembered it and was a well function box. Warranty has long gone :) and don't want any of my doing to create problem. Leaving it intact wil allow judgement to be passed on the wreckers ability to recall things correctly , if you know what I mean.

3. should it prove to be a basket case I have a back up PT 4WD box to take its place - it has 25 spline stubs too.

4. might also need to say, yep, did it with a little help from a coupla forums :)

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Our 5spds here all used 25 spline in the diff, and step down to 23 spline output for the axle stub.

 

If you split your 5spd case.....you could use a set of the stubs we got here in ours then use stock brat/brumby/ea81 axles.

 

I have a set of stubs I could ship you if you would like to go that route.

 

I have done the reverse swap to use a standard L series Dual range in a newer Legacy(liberty) car with standard legacy axles.

Gloyale, Do you still have the 23 spline stubs to fit a D/R 5 speed trans? Would make my swap so much easier, let me know. Thanks Steve

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all very well to suggest thanks Gloyale, I see yours and coxys' point entirely and was my original thinking when I pulled some 23 spline stubs from a gearbox that will never go back together again :(

 

BUT, there is a couple of reasons why I'd like to keep it a 25 spline.

 

1. as a spare for my 25 spline XT if need ever be

2. it came out of coxys' ute and neither of us know its true condition [only sat in coxys'  tray :) ] - except a fourth party supplier who test drove it, reported to me he remembered it and was a well function box. Warranty has long gone :) and don't want any of my doing to create problem. Leaving it intact wil allow judgement to be passed on the wreckers ability to recall things correctly , if you know what I mean.

3. should it prove to be a basket case I have a back up PT 4WD box to take its place - it has 25 spline stubs too.

4. might also need to say, yep, did it with a little help from a coupla forums :)

 

1.  You could easily use regular 23 spline shafts in the XT

 

2. Inspecting and reassembling would be a good idea if the condition of the box is unknown, and it has sat for a while.  Sounds like you are just not wanting to do it but it is the best way.

 

3.  PT 4wd with 23 spline are easy peasy to find.....almost all loyales had them.

 

4.  Glad to help.

 

And 5.......Even if you make 2 correct axles you will be screwed when one breaks (axles break way more often than transmission).....the more time goes on thte more this will be true as all the OE axles are going bye-bye every time someone turns in a core or junks another car.  "New" chinese will be the only options by 2020...so you better be able to use of the shelf stuff or you won't be driving your subaru anymore.

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I think the common consensus is to fit the 23 spline stub axles into the box, but I like your idea.

 

I know a good driveshaft place in Sydney. I had to get some "custom" shafts made up for my Excel. It has an Elantra gearbox (which has a diff that's 20mm wider and the car uses shafts that push inside like rear diff on WRX), and then uses the Elantra steering knuckles (so I could fit larger brakes),

I couldn't use the Elantra shafts as they were way too long, and the Excel ones (despite having the correct splines to fit the Elantra ends) were now also too long.

I showed him the spline for the inner CV, and the spline for the outer CV, along with the length required, and also spec'd as thick as possible shafts (cos I'm running a Quaife diff (hence needing the Elantra box) on tarmac motorkhanas.

He mixed & matched parts together to get what I needed.

Edited by wagonist

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