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So, those 4EAT front axle stubs.....was there a 23-spline version?

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I'm looking at getting a Carbonetic clutch-type front LSD to put in the brat. It uses 4EAT-style axle stubs.....

 

So, AFAIK, the 4EATs were only available behind the ER27, EA82t, or EJs, which would mean 25 spline stubs.

 

Any chance the 3AT stubs would work?

  • Author

Cool, didn't know that.

 

now. would that be 23-spline? A quick look on Rock Auto says that the auto-trans version uses the same front axles as EA82ts. But I don't really consider that a reliable source....

 

 

Any ideas on the 3AT? That would probably be easier to get ahold of.

88-91 XT should do it. those would be non-turbo with 4EAT.

 

all of the ea82 4eat(full-time 4wd) i have seen have all been 25 splines.

 

what about legacy rear axle stubs, since they slide into the diff much like a 4eat?

  • Author
what about legacy rear axle stubs, since they slide into the diff much like a 4eat?

 

I'll see what I can find. But I'd bet the inner splines are different.....

 

 

a quick look in my '88 XT FSM. They only list the 4-cyl and AT as a FWD option. And definitely using 25-spline stubs.

 

 

 

I think there's a slightly better chance of the 3AT fronts working, but I'm not holding my breath. I think I'll be building hybrid axles....

the one FWD XT MT i saw was 23, guess they just mixed it up between auto/manual?:confused:

hope the 3AT or something works out for you.

 

wonder if any foreign market jokers would have something, like they used different combo's over there? or maybe 4EAT's just never got 23's.

Edited by grossgary

  • 10 months later...
  • Author

Bump.

 

 

I now own a Carbonetic front LSD, which is designed to be used with the stubs from a 4EAT.

 

I just slipped a 5MT stub into it, and it fits perfectly. So, the only difference is the circlip vs. snapring.

 

 

Seems to me that would increase the chances of a 3at stub working. Otherwise, if I can get my hands on 23-spline MT stubs, I may be able to use them with circlips...

Bump.

Otherwise, if I can get my hands on 23-spline MT stubs, I may be able to use them with circlips...

 

any of the EA82 non-turbo 5-spd stubs will work.

 

I've got several in the shop if you really can't find any.

  • Author
any of the EA82 non-turbo 5-spd stubs will work.

 

I've got several in the shop if you really can't find any.

 

Yea, they're not rare, but I don't have any, and don't want to buy a transmission (or tear one down in a junkyard) for them.

Otherwise, if I can get my hands on 23-spline MT stubs, I may be able to use them with circlips...

 

this won't work, the circlip won't fit into the slot that the snapring goes, I've have 23 spline and 25 spline MT and 25 spline auto shafts all out at the same time and compered them.

 

why not just use 25 spline ea82 axles and swap in ea82 suspension and upgrade while your at it.

  • Author
this won't work, the circlip won't fit into the slot that the snapring goes, I've have 23 spline and 25 spline MT and 25 spline auto shafts all out at the same time and compered them.

 

why not just use 25 spline ea82 axles and swap in ea82 suspension and upgrade while your at it.

 

I thought that might be the case. I'm thinking a few careful minutes with a dremel could fix that though.

 

I don't know what all is required to swap to EA82 parts. I have heard the opening for the strut is a different size, which would be a problem, as that's where my lift block is...

I imagine you've already though of it, but I'll ask anyway out of curiosity.

Anyway to build a hybrid axle? Outer cv cup, outer joint, axle shaft, and inner joint from your car, inner cup and stub from the 4eat car? Possibly inner joint from the 4eat car if the EA joint won't fit in the 4eat cup?

  • Author
I imagine you've already though of it, but I'll ask anyway out of curiosity.

Anyway to build a hybrid axle? Outer cv cup, outer joint, axle shaft, and inner joint from your car, inner cup and stub from the 4eat car? Possibly inner joint from the 4eat car if the EA joint won't fit in the 4eat cup?

 

It is possible, but can be a pain. Due to all the variations in shaft diameter, spline count, cup diameter, etc. It's a crapshoot finding the parts needed. And since this is a lifted rig, with low gears, LSDs, and EJ power, I expect to break axles. I'd much rather do the work now, so that I don't have to every time I break them.

I thought that might be the case. I'm thinking a few careful minutes with a dremel could fix that though.

 

I think you would need to cut in a whole new slot for the circlip, I tryed putting 4eat sub shafts in place of 23 spline MT subs but the circlip didn't make it out the other end of the side gear it sat too far down the shaft, so I think you would need to cut a new slot a little father down the 23 spline shaft to keep it from being loose.

 

And fyi the 4eat stubs I was trying to use were out of like a 97 outback and had the same inner spline count as the 23 spline stubs in the 87 trans so you shouldn't have any problems with inner spline count if that diff is made for a newer gen trans.

  • Author
I think you would need to cut in a whole new slot for the circlip, I tryed putting 4eat sub shafts in place of 23 spline MT subs but the circlip didn't make it out the other end of the side gear it sat too far down the shaft, so I think you would need to cut a new slot a little father down the 23 spline shaft to keep it from being loose.

 

And fyi the 4eat stubs I was trying to use were out of like a 97 outback and had the same inner spline count as the 23 spline stubs in the 87 trans so you shouldn't have any problems with inner spline count if that diff is made for a newer gen trans.

 

That's interesting. I'm but opposed to cutting a whole new slot if that's what it takes. Next time I'm out at the shop, I know there are a couple junk 4EATs, so I'll pull a stub and see how it compares.

 

Yea, the Carbonetic website says it requires AT WRX stubs, but lists the part number, which turns out to be good for all 4EATs. But once it arrived, I tried one of the 5MT stubs I had (88 XT6, 92 Legacy, or 94 Impreza), and it fit perfectly. But, this is a clutch type diff, so I can't see where they are inside.

 

Good news is, these stubs will be removable without opening the case...

  • 3 weeks later...
  • Author

Still haven't been to the shop....

 

BUT, I picked up a pile (6...) of free EJ axles. One was a front with a 4EAT stub still in it. So it was just a matter of pounding out the pin and comparing it to a 5MT one that I have.

 

 

Ioku was exactly correct (not that I doubted him, just cool to see it in a side-by-side comparison). The notch for the circlip/snapring is in a different place. But, other than that (and a slight taper on the end of the 4eat stub), they are essentially identical.

 

IMG_20120602_201548.jpg

4EAT on the left, 5MT on the right. Sorry they're not lined up very well, but you can still see the differences.

 

 

 

Not sure if I want to cut a notch like that by hand, with a dremel. I might test it on a 25 spline one and see how it looks. I will certainly get a quote from a machine shop, though

Not sure if I want to cut a notch like that by hand, with a dremel. I might test it on a 25 spline one and see how it looks. I will certainly get a quote from a machine shop, though

 

It could be done easily chucked into a lathe.

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