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Legacy 4EAT into EA82 Turbo

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So my 89 GL turbo wagon decided the 4eat was done. 3.7 ratio and 27x8.50 tires don't make a good combo I guess.

 

But I have a 3.9 4EAT and rear diff from a 94 Legacy. My plan is to remove trhe bell/diff housing from the EA82 3.7 trans, and use it on the 3.9 EJ trans.

 

Obstacles:

 

3.9 diff will need swapped into the EA bellhousing. This will help my big tire dillema

 

Different harness. I had hoped to pull the whole harness form the EA trans, and put it in the EJ trans. Unfortunately, all the solenoids have different connectors, so it's not a simple swap. If the connectors weren't so brittle I could repin them to match the GL harness. But as it is, I will just leave the EJ harness and solenoids, and cut and solder the main plug to match the GL's harness.

 

 

Final question is about the valve body. The EJ trans has one more detent in it than the EA. EA used a button to control 1st hold, were as the EJ has a position for it on the shifter.

 

I'm doing my own research, but does anyone know first hand if the EA's 1st hold button will still function when mated to the EJ trans? Or will I need to use the EJ shifter with all four forward gear positions?

 

GL's TCU cannot make the Legacy Trans shift into "1st Hold" normal function. The shifter must be modified to allow it to travel 1 click further for 1st gear. Additionally, one must first shift to second, press the "1t hold" button and wait until the dash display for it lights, then pull the lever back to the new, modified 1st click.

 

Pics to be posted tommorow.

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I think they did that on the 4EAT equipped EA cars in order to not have to modify the existing three speed gear shift mechanism, but I do not know how the 1st gear hold switch works, if it moves the cable another detent, or of it just electronically holds it in first. You might have to swap the Legacy shifter mechanism in. Aside from that, I have no clue what other differences might exist between the EA 4EAT and the EJ 4EAT.

 

If I were you I'd just swap to a 5 speed :banana: I have a good 5 speed, granted it's a turbo 5 speed so it's 3.7, but it's one of the dual range part-time boxes that are hard to find...

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I think they did that on the 4EAT equipped EA cars in order to not have to modify the existing three speed gear shift mechanism, but I do not know how the 1st gear hold switch works, if it moves the cable another detent, or of it just electronically holds it in first. You might have to swap the Legacy shifter mechanism in. Aside from that, I have no clue what other differences might exist between the EA 4EAT and the EJ 4EAT.

 

I believe it holds 1st electronically, by mean of the shift solenoids A and B. the EJ trans should be capable of doing the same thing. The TCU will try to operate it the same I figure since I'm retaining the TCU from the 89. But I didn't fully dissaemble the valve body to examine if passages are different.

 

If I were you I'd just swap to a 5 speed :banana: I have a good 5 speed, granted it's a turbo 5 speed so it's 3.7, but it's one of the dual range part-time boxes that are hard to find...

 

 

Really? I was considering getting the one that Slideshow had up in Olympia, but he returned it. I wanted to do a five speed shop, but getting the car up and running with on hand parts sounded good. I also don't have money for Clutch, pedals, cable, driveshaft, and depending on what trans I used, axles. I was and still am considering a 23 spline, 3.9 D/R. You're 3.7 would match my diff and axles though......hmmm....

 

Perhaps I could get the 5peed from you, and intstall it when I put the full rebuilt motor with Spider intake in. I have had it sitting around for month but no time.

 

I have to come in to J+Ps tommorow to get TQ seals. Do you work tommorow?

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it's possible to make this work, i know someone that has done it. he is supposed to send me some tips/instructions but haven't yet. i only have a few bits and pieces from exchanging emails with him, here is the most detailed i have (XT6 and EA bellhousings are identical):

 

"To make the legacy trans fit the XT6 you actually have to change the front housing due to the bolt pattern.

However you can actually use the legacy series diff. I actually pulled the front off and used the original XT6 diff as it has 3.7 ratio and 1:1 drive ratio. The Ej series uses a 1.1:1 ratio. and i didnt have the correct rear legacy diff."

 

i emailed him again....

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However you can actually use the legacy series diff. I actually pulled the front off and used the original XT6 diff as it has 3.7 ratio and 1:1 drive ratio. The Ej series uses a 1.1:1 ratio. and i didnt have the correct rear legacy diff."

 

 

 

hmmm... well I'm going to use the EJ Front diff, and the matching 3.9 rear diff.

 

But are you saying hte diff in the EJ tran may already be 3.7??? with 1.1:1 reduction to use a 3.9 rear?

 

I want to keep the EJ diff mated to it's original pinion shaft. I don't want to have to swap that and deal with spacing issues. Plus 3.9 will help me turn my big tires easier, wihtou throwing off the millage too much. If this works well, I may consider a 4.11 or 4.44 geared box in the future.

 

At this point it seems that the hardest part will be setting backlash.

 

Everything else is typical Subaru=Lego style swap.

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are you saying hte diff in the EJ tran may already be 3.7??? with 1.1:1 reduction to use a 3.9 rear?
i don't know, i just copied that from his email. EJ's aren't 3.7 i don't think, but i don't understand that 1.1:1 comment as i've never done any diff/gear work like that.

 

he said he has good details on doing this swap but hasn't sent them to me yet. said's it rather large and he couldn't email it so he's shipping it via CD, from another country. has to have pictures to be that big?

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The old 3at had a tranfer ratio of .948:1 (37/39).

3.7 front ratio and 3.9 in the rear.

 

If the EJ 4eat is the same, I don't have to swap front diffs. It will already have a 3.7 front diff. I need to go and count teeth. I'll still need to put in the rear 3.9....unless I swap transfer gears.......hmm.

 

But overall, I won't get any more gear reduction:(:mad: Damn.edit: yes I do!!!

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Ok. Update. I counted today and as I originally suspected:

 

EA82 number of teeth ring/pinion = 37/10=3.7

 

EJ22 (legacy) number of teeth ring/pinion = 39/10 =3.9

 

These numbers match the rear diffs for the respective cars. So it appears for at least these 2 models of 4EATs, The transfer ratio (or 1st reduction ratio a the FSM term it) is 1:1.

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Pictures!!!

 

Legacy trans on the left, GL turbo on the right

DSCF0053.jpg

 

again from looking at the front

DSCF0054.jpg

 

8 marking on the Legacy(3.9) pinion

DSCF0060.jpg

 

9.8 marking on the GL Turbo(3.7) pinion

DSCF0061.jpg

 

And the matching mark on each diff/ring gear assembly

DSCF0064.jpg

DSCF0065.jpg

 

Legacy diff transplanted into the GL turbo Bellhousing. With the old GL(3.7) diff sitting on the table. Note the matching color of the speedo gears, I swapped them as well. Held on with a a circlip. Left stub shaft of the 3.7 diff is removed for example of how they come out.

DSCF0063.jpg

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nice photos!!

 

Thanks for the "insider's look"

 

and detailed explaination!!

 

 

I have a speedo gear swap in my future

these will sure help me get a

mind's eye view of what to expect.

Thanks again.

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I have a speedo gear swap in my future

these will sure help me get a

mind's eye view of what to expect.

Thanks again.

 

So for you're speedo gear, here is what I would expect to need to do.

 

First the bell/diff housing needs to come off. Easy.

 

*Note that you will need to order from Subaru a *tube seal* big long tube that seals the mainshaft from the diff. As well as the *ring seal* and front TQ seal.

 

The diff needs to come out to access the speedo driven gear. So the caps need unscrewed. mark there excact position with a paint pen. Then count the # of turn out. Some notes on this:

 

1. A special tool would be nice, but I just used a punch to gently nudge the cap around. Hard hits will break off the little ears. Once It had gone a half turn, I used a big pair of channellocks, spread wide, as a sort of Spanner wrench. After the first turn, it will spin pretty easy.

 

2. You don't want to loose track of how many turns out. Since the caps have a large unthreaded portion that extends into the housing, you need to actually be pulling outward as you count and unscrew. Otherwise once the threaded portion releases, it can still *feel* like it's unscrewing, but you're just feeling the unthread portion spinning in the housing. Espescially since it ha an O-ring on it holding it snug.

 

3. After removing both caps, and the diff, it's really easy to access the snap ring for the driven speedo gear.

 

4. I don't know anything about replacing the drive gear on the Diff. Good luck.

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Yikes!!

 

Thanks Gloyale,

that is some

serious good and detailed info for

anyone pulling apart a front diff.

 

For whatever reason.

 

 

It may have been covered before somewhere

but with your pictures...

(thousand words an all that)

well done.

 

Thanks again,

 

now about getting the smell of gear lube

out of......

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now about getting the smell of gear lube

out of......

 

 

Yeah..... good luck with that.

 

I have a jacket I keep at my shop. Whatever you do, don't carry the diff anywhere in a car you care about. It will smell bad for days and potentially.......forever....WAHAHHAHHAHAHAA:lol:

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More pics

 

GL Turbo diff/bell on the left, Legacy on right.

DSCF0052.jpg

 

Legacy(ej22) diff/bell with an EA82 rear of engine bellhousing. Can you say adapter plate template????

DSCF0066.jpg

 

And one more of the 2 housings. And the front clip of the donor Legacy. DSCF0068.jpg

 

Tail end of the two cases. The transfer clutch bolts on here. This side appears identical. However there are a few differences on the tansfer clutch side. No pic yet. Soon.

DSCF0067.jpg

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the speedo gear swap does not require splitting the case. you can just remove the axle, then remove the bolt for the bearing retainer, then unscrew the passenger side retainer, and pull the bearing. Then you have to pull the stub. The speedo gear will slide right off. no need to open the case, i did this with my 94 turbo leg, and the tranny was still in the car. there are a couple of large o-rings that will need replaced.

 

don't do this unless you are familiar with diffs. must measure tolerances, by a similar method as needle settings. mark the current setting on the retainer, count the turns in until bottom out. unscrew. when it goes back together, do the same number of turns from bottoming out.

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the speedo gear swap does not require splitting the case. you can just remove the axle, then remove the bolt for the bearing retainer, then unscrew the passenger side retainer, and pull the bearing. Then you have to pull the stub. The speedo gear will slide right off.

 

area you serious? i've asked about this a number of times. i think skip and I would love to hear more from you about this. i have the same problem.

 

my question is this - i imagine there's the speedo drive gear and a driven gear right? there has to be two that come together. are they both replaceable this way or only one?

 

if it's the gear that's around the diff that's bad, then that won't be replaceable as easily i don't think.

 

is one more likely to break or be damaged than the other? i imagine maybe the driven gear is mostly likely to be bad...the one on the shaft for the speedo sensor?

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the speedo gear swap does not require splitting the case. you can just remove the axle, then remove the bolt for the bearing retainer, then unscrew the passenger side retainer, and pull the bearing. Then you have to pull the stub. The speedo gear will slide right off.

 

That sounds like the hard part. That bearing is pressed onto the diff carrier. But if you can get it off, seems like that would work.

 

Gary, the "driven" gear is held on with a little spring clip. Once the stub, bearing, and "drive" gear are pulled off the diff, you should be able to get at the spring clip. Provided you have spring clip pliers with a good angle on them.

 

At any rate that's a side-note to the point of this thread hi-jackers!:lol: JK

 

I will be installing the matching 3.9 rear diff to my GL Turbo hopefully tonight. Update about the overall sucess or failure of the swap will be coming soon.

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It' in and driving. No Code from the TCU, and all shifting seem normal.

 

It does seem that there is some knocking from the tail end of the trans. The EJ tailsection is a bit bigger, and it' mounts hit the inside of the GL's tunnel.

 

Also, it seems like there may be some noise from the front diff. But I am reworking my exhaust at the same time, so my test drive was very noisy(just the downpipe). Hard to tell what I'm hearing.

 

The upside is that lower gearing and unrestricted exhaust made for a few fun 0-60 runs:clap:

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awesome! great job! while this thread is fresh could you make a list of what is EA82 and what was EJ?

 

 

Car is an '89 GL Turbo wagon

 

Originally equipped with 3.7 ratio 4EAT.

 

Now is running 3.9 ratio 4EAT, from '93 Legacy

 

GL parts used:

 

engine, TCU, crossmember, drvieshaft

 

Front diff/Torque converter housing.

 

 

Legacy parts used:

 

Center and rear(transfer) Transmission sections.

 

Torque converter

 

Front 3.9 differential, ring, and pinion

 

Rear 3.9 Differential

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New info discovered.

 

This is the question posed in post #1 of this thread in red.

 

Final question is about the valve body. The EJ trans has one more detent in it than the EA. EA used a button to control 1st hold, were as the EJ has a position for it on the shifter.

 

I'm doing my own research, but does anyone know first hand if the EA's 1st hold button will still function when mated to the EJ trans? Or will I need to use the EJ shifter with all four forward gear positions?

 

Answer:

GL's TCU cannot make the Legacy Trans shift into "1st Hold" normal function. The shifter must be modified to allow it to travel 1 click further for 1st gear, to phyisically pull the cable further. This mimics the Legacy shifter.

 

Additionally, one must first shift to second, press the "1t hold" button and wait until the dash display for it lights, then pull the lever back to the new, modified 1st click.

 

If you just pull the lever back the extra click it will use only 1st gear. However... it does not lock the Torque Converter to provide engine braking, important for slippery descents. And also does not provide the Increased Transfer clutch pressure of the *1st hold* mode.

 

The TCU need the electrical signal to control 1st gear. Without it, it won't fully use *1st hold*. Seems now what I have is like the Legacys *Normal* and *MANU* 1st modes.

 

I reused the GL's indicator switch, which only goes down to *2nd*, So the signal for 1st has to come from the seperate *1st hold* switch. On the Legacy, the signal for 1st come from the indicator switch on the side of the trans.

I am going to attempt to use the legacy indicator switch, rewired to signal *1st* hold

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Well, it works.

 

seem the larger Legacy tail section i a bit of a tight fit for the GL. Even with a BFH massage, it still is knocking around inside the tunnel a tad.

 

Also, I don't think I got the Ring/pinion spacing quite right, cause it' making a rumbly dragging sound like a wheel bearing, but it's not at the wheels. It' hard to know however, because I don't know the condition of this trans. I found out from the previous owner of the donor car, it was "rallied" alot. He says they took it "jumping"(maybe that explain the 45 deg. bend in the pitch stopper:lol:), and sounded very surprised that I used the transmission from it. Like he couldn't have told me that before I gave him $100 for the car???

 

At any rate it 4 wheels like a MoFo now with the lower gearing. And nothing broke hammering on it up hills and over waterbreaks. So I'm running it.

 

I consider the concept proven. Next time I'll use a newer, known good trans. And I'll be even more excacting about ring/pinion spacing.

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On a hunch today I inspected my wheel bearings, and found the drives side has been the cause of the low rumble. I was so focused on the trans I overlooked the first obvious culprit for that type of noise. Additionally, The axle on that side felt weird so I swapped it, and the odd, clunk/crunch I had been hearing occasionally disappeared. I was too worried about the trans and forgot that other stuff could be wrong.

 

So now she runs like a champ. Quiet and noise free. Except the tunnel is definately too small. The trans is still bumping the tunnel when it shifts under load. Minimal. I can deal with it for my offroader.

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Just as a side question, could a person go the opposite direction and use the bell housing off an EJ on the turbo trans with the turbo diff to install a 2.2 in an 88? Are all the inputs to the trans comp electrical?

 

I have a nice 88 body and would like to replace the original 3at with a 4eat for my wife ( no 5 spd she uses hand controls ) who loves her car but would like to have some more power.

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Just as a side question, could a person go the opposite direction and use the bell housing off an EJ on the turbo trans with the turbo diff to install a 2.2 in an 88? Are all the inputs to the trans comp electrical?

 

I have a nice 88 body and would like to replace the original 3at with a 4eat for my wife ( no 5 spd she uses hand controls ) who loves her car but would like to have some more power.

 

Well it sound like you want to just swap in an EJ motor and tran. No bell or diff swapping required.

 

What would be required is getting the TCU for the transmission and wiring it in. The old 3AT is all mechanical, where the 4EAT is electronically controlled by a brain, and needs to see signal from the TPS. o therefore can only easily be mounted to a FI engine.

 

It would be a great idea for a swap, for anyone that already has a GL turbo or XT with a 4eat in it. Swap on a EJ bell to you're tans and woola! no adapter plate needed!!

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