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23 & 25 spline DOJ conversions


kiwishooter
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This seems to be a common problem when doing gearbox swaps.

 

Since I'm putting a EJ22 and Legacy D/R hybrid FT4WD gearbox into my Brumby (Brat) I had the problem of tyring to refit the front axles, here is the solution I found.

 

I wanted to use parts that were easily obtainable, therefore easy to replace, with no machining.

 

Taking the Brumby 1/2 shaft I removed the outer cup from the inner DOJ, this cup has 23 splines to fit the early gearbox.

 

Then taking a Legacy 1/2 shaft with the 25 spline inner DOJ I removed the outer cup from the DOJ.

 

I then put the outer cup from the Legacy DOJ onto the inner part of the Brumby DOJ.

 

Now I have a 1/2 shaft that will fit the Brumby hub and fit the Legacy 25 spline gearbox stub axle.

 

You could also put the Brumby outer DOJ cup onto the Legacy inner part of the DOJ and therefore end up with a 23 spline inner DOJ that will fit the Legacy 11/2 shaft.

 

I haven't looked to see if this could be done on a outer CV but it may be able to be done.

 

Hope this helps somebody looking at doing a swap.

Edited by kiwishooter
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The problem is that I couldn't find any 23 spline stubs that would fit into the Legacy diff carrier. All the EA82 gearboxes I looked at were 25 spline unless they were 2wd which were 23 spline.

 

All the 23 spline stub axles I found were 23 splines on the inner end and the diff carrier bearings were quite a bit smaller than the Legacy 4wd diff carrier, so you couldn't just change the carrier either.

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Not all EA81 axles have the same joint sizes - and this goes for Legacy's as well. We have known for a long time that it can be done but what no one ever bothers to check is which axles it takes to do it. EA81's axles come in two flavors and the Legacy axles come in two, maybe three more. That's a total of 4 or 6 combinations of joint components - not all of which will work. It's not as simple as it first appears - especially if the first one you try works as seems to be the case for you.

 

GD

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all the older EA81 short shafts with the 23 spline cups i have seen use a different shaft spline so the DOJ will not fit on at least not any OEM shaft .

 

if you have a 80-84 short shaft for a EA81 car

 

with 85-90.....EA-EJ 25 spline cup on it

 

i would like to know what early short shaft you used ?

 

the splines are similar but are not exactly the same that they fit .

 

nothing is written in stone so maybe at some point they changed the the shaft splines in the later EA81 cars but we didnt get many here after 1984 except the hatch / Chaser .

Edited by rguyver
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I don't think he's talking about swapping the whole DOJ - I think he's just swapping the outer race of the DOJ - the "cup" portion. Thus mixing wear components, but it will effectively yeild a working joint if you find the right size 25 spline cup to match the inner race of the stock EA81 DOJ. That way no shaft splines would come into play.

 

GD

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GeneralDisorder has it correct

 

All I did was remove the boot on the Legacy and Brumby inner DOJ's then removed the wire clip so I was able to remove the outer cups.

Then fit the outer cup from the Legacy 1/2 shaft onto the 83 Brumby 1/2 shaft refit the wire clip and the boot.

Fit the 1/2 shaft back on the Brumby.

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The problem is that I couldn't find any 23 spline stubs that would fit into the Legacy diff carrier. All the EA82 gearboxes I looked at were 25 spline unless they were 2wd which were 23 spline.

 

All the 23 spline stub axles I found were 23 splines on the inner end and the diff carrier bearings were quite a bit smaller than the Legacy 4wd diff carrier, so you couldn't just change the carrier either.

 

Strange.

 

All the Front diffs I've taken out of EA and EJ manual trans are all the same. And all the non-turbo EA trans we got here were all 23 spline.

 

Things may be different down there, but all my experience has been that the diff stubs, and the diff carriers themselves, are totally interechangable.

 

We put 25 spline stubs into a standard 3.9 EA D/R to use it in a Legacy(liberty)

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  • 2 weeks later...

Boy, it can be a mess. I recently went thru' this trying to put togather shafts for my GL/XT6 conversion. I had shafts & cups all over the shop floor, GL- XT+Leg. So many different shaft diameters, cup sizes, etc. I needed 23 inner & 27 outer, & with all the crap I had laying there I was able to build 1 shaft. In the end I went to Legacy struts & hubs with 93-4 Imp. 2wd 5 Spd. shafts. Working perfectly. Thanks, S.

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Strange.

 

All the Front diffs I've taken out of EA and EJ manual trans are all the same. And all the non-turbo EA trans we got here were all 23 spline.

 

Things may be different down there, but all my experience has been that the diff stubs, and the diff carriers themselves, are totally interechangable.

 

We put 25 spline stubs into a standard 3.9 EA D/R to use it in a Legacy(liberty)

 

Ah now this makes sense, down here in NZ the diff's aren't interchangeable, well none that I have found. The 23 spline diff has a bearing that is about 10mm smaller in diameter than the 25 spline diff so you can't change the diff.

All the EA non turbo boxes are 23 spline while the Turbo EA didn''t come to NZ that I have seen. All the L series non turbo that I have seen were 23 spline and the Turbo were 25 spline. While the Legacy and Impreza 2wd were 23 spline all the 4wd were 25 spline.

The 23 spline stubs have 23 splines on the inner and outer end, and the 25 spline have 25 spline on the inner and outer end. So trying to fit a set of 23 spline stubs into a 25 spline diff is like fitting a 25 spline DOJ onto a 23 spline shaft.

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  • 5 years later...

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