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Do EA82 Front CV-shafts differ? Manual/auto, different lengths..


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hi,

 the inside(transmission end) doj will be either 23 spline or 25 spline,  the diameter of the spline section  also differs,  according to which spline count it is.   the 23 will not phisically fit on a 25 spline trans ,,, but a 25 doj  can be put on a 23 spline trans, ,  but it  definately causes problems!!  but when folks don't know,  it does happen.. bad juju!   the corrosponding transmission stubs will also be 23 or 25 spline and sized to match,  it is the turbo version trans and perhaps the later ea82 with the 4speed auto trans that used the 25,  most common is the 23 spline and is used in many more of the vehicles.  they list different part # for auto or m/t  but they seem to interchange without issues as long as the spline count is right. , the outer end is the same on all of them so far as i know.  the shafts itself has some different markings but i believe they are all within the range of whats called interchangable,, the fsm has a section as to what the different markings are and what they indicate,  basically it is the number of rings, and their location on the shaft,  that is shown,,  these are raised ridges forged with the shaft originally and easy to see.  oem subaru joints are better quality than the aftermarket so it's better to rebuild an original than buy a rebuilt usually,, if it has not been run tooo long without a boot.  the complete ea82 shafts do not fit the ea81 vehicles.

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Is it more of a guess that automatic and manual transmission 23 spline axles are the same, or is it a positive "definitely" the same?

 

They use different thickness shafts and different joints, but are effectively interchangable.  The FWD automatic axles are thicker with a bigger joint.

 

The length and splines are the same, that's all that matters.

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They use different thickness shafts and different joints, but are effectively interchangable.  The FWD automatic axles are thicker with a bigger joint.

 

The length and splines are the same, that's all that matters.

I would go so far as to agree on the difference in thickness, however from what I've experienced with EA81 CV shafts, the length can differ too.

In fact, as the automatics sticks out more (EA81 cars) the shafts are thicker and shorter.

 

Let's see if someone can verify this for EA82 cars.

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I would go so far as to agree on the difference in thickness, however from what I've experienced with EA81 CV shafts, the length can differ too.

In fact, as the automatics sticks out more (EA81 cars) the shafts are thicker and shorter.

 

Let's see if someone can verify this for EA82 cars.

 

 hi,

  just look in the chart that Dee2 posted a link to in his post above,, the top section of it shows the length of the various shafts, ( L ) dimention ,  and their identifying markings in another section.  the thickness of shaft and joints is not in there,  but they range in length between the boots (FSM measurement points) is 9.53" -- 10.12" -- and 10.43"  so there are some variations in length ,, all the 25 spline doj shafts are the shortest ones,  and there are some 23 spline ones that have the shortest shafts,,,  the other 2 longer lengths are both with 23 spline joints,  so you have to go to the markings to determine which actual shaft length version is the one you have.  

  there is a great deal of information and variation contained in this chart so take your time in going over it , , all said there can be almost an inch difference in length of the shaft itself,  chart does not say if there is any difference in the portion of shaft within the boot, but since the inner doj"s  have some variations,  it could mean the shaft length change was made to compensate for a joint difference, and the overall length of the total assembly is still the same for all ??   no one really knows because its just so convoluted and you'd need a pile of ( original)  ones  to measure all the variations  to really find out.  and then there is the compressed length and the extended lenght both to concider,, wow.  

 for average cars doing daily use , mostly we have found all them to be ok to use if the splines match the trans stubs, that is on the ea82 series cars , at least the 3at and M/T , 4eat trans i cannot comment there except to say they have 25 spline stubs and so used the shortest shafts originally according to the book.

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I would go so far as to agree on the difference in thickness, however from what I've experienced with EA81 CV shafts, the length can differ too.

In fact, as the automatics sticks out more (EA81 cars) the shafts are thicker and shorter.

 

Let's see if someone can verify this for EA82 cars.

 

All EA82 axles are the same length

 

All EA81 axles are the same length

 

Period......  Length between where the boots attach is irrelavent. Think about it....each chassis is the same width, using the same knuckles, and same trans mounting points (AT and MT diffs are the same width)

 

For a given chassis.......all axles are the same INSTALLED length. (off the car you can stretch and compress them...so that comparison is flawed)

 

 

Snatched.....I think you may have gotten an EA71 (first gen) axle at some point.

 

The only thing that varies is axle thickness, the cup/joint size, and the spline count (25 on turbos)

 

This thread is just going to confuse people.

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//"...


 

Period......  Length between where the boots attach is irrelavent. Think about it....each chassis is the same width, using the same knuckles, and same trans mounting points (AT and MT diffs are the same width)

 

For a given chassis.......all axles are the same INSTALLED length. (off the car you can stretch and compress them...so that comparison is flawed)


...


 

The only thing that varies is axle thickness, the cup/joint size, and the spline count (25 on turbos)

"//

 

 

I'm sorry but "all axles are the same INSTALLED length." is even more confusing and misleading. That's as if you said, if the part will fit the car, then all of the shafts in that category are the same length ??

 

You said yourself that they all stretch and compress to different lengths,

from what I've seen from local and online merchants, the CV shafts are specified by compressed length only.

 

..if each part has it's own compressed and stretched limits, then each has a different minimum and maximum length.

I'm pretty sure that affects fitment and proper function on the vehicle.

 

To date I had 27-3/4", 27-1/4", 25-3/4", and a 25-1/4" compressed length shafts.

~The first two were simply not going to bolt on, they were too long, or the head was too fat at the spindle, not allowing it to sit flush.

~The last one was just too short, fully stretched and not bolting on. EA71? This one was also very fat in thickness (not relevant I guess).

~The 25-3/4" compressed length shaft is just long enough to bolt on, but compared to the original shaft I had, it is stretched at least half an inch more. The original shaft bolted on wheel side, then stretched a bit and was pinned to the engine side hub. This aftermarket part stretched approx. the same amount, then almost 3/4" more before the pin would be able to fasten.

 

The cv shaft started to chatter within a week...

 

(OK so different heads can affect fitment, does each Subie have it's own head size?)

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