EA82 5 Speed Q

[carfreak85]

Will the center diff portion of an RX transmission bolt on the rear of a regular EA82 5 speed? I assume there is no ring gear or ratios to match up in the center diff.

[GeneralDisorder]

No - the FT4WD box shares many components with the early Legacy trannies. As the regular D/R has no center diff, there's no place for one to go in there. You can install the low range gear set from the regular D/R to the FT4WD D/R though.

 

GD

[Subarutex]

I'm sorry, I disagree GD. I believe it to be workable. I just wanted to get all the pieces and have a running example before posting a thread so we can all speculate about it.

 

Galen, I'm rather offended you brought this here. A simple yes i'll sell you the broken tranny, or no I won't would have been enough.

 

I was hoping to use my old RX tranny that Galen now has that has a borked shift rod. Because then if this doesn't work, I won't be dissassembling and potentially ruining a perfectly good, rare, RX trans.

[GeneralDisorder]

Hhhmmm - I beleive it was discussed in the thread about installing the N/A low gear and 4.11 diff into the RX tranny. I'm pretty sure there's no place inside the N/A tranny for the center diff to go. And even if it were there in the casing, you would need to have machine work done for the diff lock mechanism, etc. Also shimming it correctly requires special tools, etc..... it's better, if you want something like this, to take the low range from the N/A and put it in the RX case.

 

GD

[Numbchux]

but isn't the center diff portion of the casing seperate from the rest? I know it is for the EJ trans, and the FT4wd ones. and the bolt pattern for said center diff casing is interchangeable from one to the other....

 

the question is the pinion gear. will the N/A PT4WD 3.90 pinion gear work with the FT4WD center diff. you may have to switch it for a 3.70 pinion....

[Subarutex]

Hey Look! Its theory and speculation!

 

Basically, think of the transmission as having 2 pieces: Piece 1 being the front diff/5speed area; Piece 2 is everything behind that D/R, center diff or straight rear output.

 

Why wouldn't the pinion gear be the same? My reasoning is from the different variations of these trannys.

 

3.9 5spd d/r

3.9 5spd pushbutton

3.9 5spd FT4WD w/ diff lock

3.7 5spd pushbutton

3.7 5spd FT4WD w/ diff lock

3.7 5spd FT4WD D/R w/ diff lock

 

Now... with what we know about how cookie cutter these cars are (Phizina's swap for example) why would the output portion of the tranny change between all these variables? It seems for cost reasons, they'd keep as much alike in these trannies as they could.

 

So in theory you could remove the back half of any of these transmission and mate it with the fronts. Sounds so simple right? Right. Of course, its never as easy as it sounds, but thats why someone needs to try it.

 

Also, FYI - I'm not out to put together some Ultimate Gearbox that ShawnW, NoahDL88, and all those people are clamoring for. I don't need 4.11 gears in my wagon (my RX has them), I don't need NA D/R gearing (who offroads subaru's anymore?).

 

I do need FT4WD w/ the ability to lock it up if I want. EJ22 on 28" swampers makes it hard to get up damp hilly streets in FWD. Keeping it 3.9 just means I don't have to swap my rear diff, and lose my welds.

 

And, if my plan doesn't work... I'll just throw in an RX box, weld up a 3.7 rear and call it good.

 

Ready....

 

 

 

Set....

 

 

Argue!

[carfreak85]

Galen, I'm rather offended you brought this here. A simple yes i'll sell you the broken tranny, or no I won't would have been enough.

 

Um, sorry? You never said anything except, "I want to experiment". Nothing about putting a diff on any other tranny, what plans you had for it, or any information that would have been useful to figuring out what you were going to do. Now using my powerful skills of deduction, I deduced that because I wanted better gearing for my EA81T and that I had a good center diff, why not throw something out on the board (Thats what the USMB is all about SHARING ideas, not arguing) to see if they might fit together. I made no mention of a transaction between myself or you, or anything for that matter... Until you posted. I was only trying to glean some information to aid in my decision to keep or sell a junked tranny. [/rant]

 

Oh, one more thing Chris. I still have a bunch of pics of the URX from WCSS8 if you still want them. Ex:

 

[Subarutex]

Galen, sent you a PM... and yeah, i'd love those pictures.

 

You are right, this forum is about sharing, however it should not be about sharing mis-information... and thats all I could see coming up.

 

So... lets try this, someone. Post the results. Hit me up if you need help, i'm more than ready to try this out!

[Numbchux]

well, I've got an early legacy 5-speed AWD tranny apart in my basement. which we know the center diff section is interchangeable with the EA82 FT4WD center diff section (as demonstrated by both Beafaru and Phizinza, who have opposite combinations of the 2). my camera is charging now, but I can take some pictures and measurements of it, if that would help. I don't have a n/a PT4WD trans, though...

[Subarutex]

Yeah... post the pics!

[baccaruda]

how complicated is this swap?

 

 

early legacy 5-speed AWD ... center diff section is interchangeable with the EA82 FT4WD center diff section

[Numbchux]

how complicated is this swap?

 

well, check out phizinza's swap. it doesn't look too tough at all:

http://www.ultimatesubaru.org/forum/showthread.php?t=71100

 

although he's starting with a D/R EJ trans, but you get the idea.

 

once I get my hands on this RX trans from a buddy of mine, I'll be able to tell more definitely. the biggest problem is the pinion gear. if you look at Phiz's pics, you can see the pinion shaft sticking out a good 6-8" by the looks of it, from the output shaft on the tranny. whereas the EJ pinion that goes with the viscous center diff only sticks out a couple inches.

 

I'm at school now....so no pics yet. it'll be more obvious what I'm talking about once those are up.

[baccaruda]

so swapping the center section means swapping the pinion gear as well. Which means that any gear ratio changes should be done at the same time.

 

I'd be keeping the EA82 trans case if I do any such thing...

[Numbchux]

so swapping the center section means swapping the pinion gear as well. Which means that any gear ratio changes should be done at the same time.

 

I'd be keeping the EA82 trans case if I do any such thing...

 

 

yep, it appears that the difficulty in swapping the front axle ratio, is mating the pinion to the center diff section. if you're using an EJ viscous center LSD, than any EJ 5MT axle ratio is possible. which explains Beefaru's 4.11 RX trans...he's got the matching EJ viscous center.

 

here's a pic of Phizinza's hybrid creation, for comparison

notice the FT4WD pinion, sticking way out the back of the output shaft.

 

almost the exact same view, with a stock EJ 4.11 pinion:

 

and from straight on, this is the front of the EJ center diff section. on the trans side.

if this piece is interchangeable with the PT4WD D/R 'transfer case'. a 3.90, 1.59:1, FT4WD tranny might be pretty easily made. the question there, is if the PT4WD 3.90:1 pinion is the same as the FT4WD 3.70:1 pinion.

 

 

if someone wants to give me $85, I'll go out to Chesney's auto salvage here in town, and buy a D/R PT4WD trans, and take it apart to see. otherwise...it'll have to wait :-\

[Phizinza]

I know for a fact that you can use the crown wheel, pinion gear (which is all part of the shaft) and the output gear set of the FT4WD box in the PT4WD EA82 box with the rear center diff locker rear end casing. Because that is what the FT4WD box I got was... It had already been swapped around.

 

You cannot put the center locking diff or VLSD in the PT rear end (not 100% sure, about about 99% sure.) I'm also 99% sure you can't put the VLSD in the locker casing or visa versa.

 

I believe the S/R FT4WD XT6 trans came in 3.9... This means you can use it's crown wheel and pinion shaft to get a 1.59 D/R 3.9 FT4WD box.. Again, only guessing, as I haven't seen a XT6 FT4WD trans (well hell, I haven't seen a XT6 in the real as we never got them here. But then again, we never got FT4WD boxes either, the oine I have is a import.)

 

If you use the VLSD (which is much better for road only use anyhow!) you can have 3.9, 4.11, or 4.44 I believe.. Any pre 99 5sp manual uses the same center VLSD I believe, which means their pinion shaft much be the same. I've also seen pictures of inside a 02 WRX 5 sp (I believe that is what it was)and it was almost the same as the PT4WD EA82 box, even had a place for the low range gears over the top of the diff!

 

I'm looking for pictures of my Subaru Liberty/Legacy D/R insides now, but I think they are on my brothers phone....

[Phizinza]

and from straight on, this is the front of the EJ center diff section. on the trans side.

 

 

With a different bearing, you might be able to fit a VLSD into the FT4WD casing, this would mean you don't need to make a custom gearbox crossmember for the new EJ boxes rear end... But if I were doing this and the center locker was still good, I'd keep it with the casing and use the EJ's casing.

 

 

So, what you could build for a EA82t RX is... 3.9 or 4.11 (maybe 4.44) diff with a 1.59 low gear and VLSD AWD...

Just keep in mind you have to keep the same crown wheel on the front diff that was matched with the pinion gear. So if you have a 4.11 pinion, you need the 4.11 crown wheel. But you can run any front 5sp LSD unit you want.

[baccaruda]

I've swapped 3.7 LSDs to 4.11 a few times now so I'm familiar with matching crown wheel/ring gear to the pinion gear.. but the rest of this stuff is beyond what I've ever done.. very cool stuff, guys.

 

Chux, I'm a little lost as to what you're referring as I don't know my transmission anatomy very well.. I can see that the one pinion is longer than the other though.. thanks.

 

(Phizinza, I think you're right about the XT6 coming in 3.9)

 

Let me make sure I have this correct:

So (theoretically) you can interchange the 3.7 FT4WD pinion,etc & ring/crown with the 3.9 to swap gear ratios between FT4WD transmissions.

 

Treating the FT4WD guts as noted above as essentially identical, the theory is that you have to match the pinion/ring to the center differential when swapping between FT4WD and AWD transmissions.

 

And, Phizinza, you're saying that the center differential section and the crossmember must be matched to each other?

 

sorry for the inquisition but rephrasing what you guys have said is how I make sure I have it correctly

[Phizinza]

And, Phizinza, you're saying that the center differential section and the crossmember must be matched to each other?

The EJ VLSD center differential casing has different mounts to the EA82's mounts. So it needs a modded crossmemeber to fit in a EA82 car.

 

The pinion gear is attatched to the pinion shaft.. If you want the diff locker, you must have 3.7, unless you can find a XT6 3.9 FT4WD M/T gearbox..

 

If you want VLSD center.. Well then you find an EJ gearbox with the right ratio you want and use it's crown wheel(ring gear) and pinion gear and shaft (remembering the gear and shaft are one piece) in the FT 4WD box.

I think the PT4WD box has a one piece output shaft.. In other works the shaft the gears are on is the same as the shaft the pinion gear is on. Where as the FT4WD gearbox has a output shaft (the one with the gears on it) and a pinion shaft that goes down the middle of it. Thus letting the front turn inderpendently from the outputshafts gears.. I'm sorry if I confuse you, this was all new to me 6 months ago before I pulled both the EJ and FT4WD boxes apart... I still need to get the PT4WD on the bench and have a look inside

 

So if you want AWD on a PT box I am guessing you need to take the output gear shaft along with the pinion shaft from the EJ into the EA, and hope the EA input shaft hasthe same gear ratio's as the EJ output shaft...

[baccaruda]

nah, I have an RX 3.7 FT4WD trans in my wagon and I really like what Beefaru has in his rig but I'm not sure whether I'd want to keep the locker or swap in a viscous. I care nothing about the PT4WD transmissions :-p but thanks for the warning. You are saying that the FT4WD pinion is a shaft-inside-a-shaft?

 

Modding the crossmember isn't a big deal compared to transmission guts-swapping!

 

I do know that I would at least like to change the ratio as he did - 4.11 ratio, Forester 5th gear for better highway RPMs - but he had a viscous center section swapped in, which fits what you're saying.

 

But couldn't the pinion be pressed off/onto the shaft by a machine shop? That would let me keep the locker (if I choose) and change the ratio. Especially if I fink with the 5th gear anyway as I'd take it to a shop for that too.

 

Didn't the STI come with an adjustable center diff? lol

[Numbchux]

yep, as far as we know...you have to match the center diff to the pinion. maybe this will help you tell the difference between the tranny output and the pinion gear (I certainly didn't understand until I turned some gears myself...):

and they can spin separately, one inside the other.

 

Phiz is suggesting (and he very well could be right...I just don't know) that those are one piece on the PT trannies. since they never spin independent of each other. so you might have to use an XT6 3.90 ring/pinion if you want to get FT4WD with it.

[Phizinza]

Pinion is part of the shaft "inside a shaft." As in it is machined, not pressed on

 

What I would do with your RX is build up a non-turbo 5sp with the gearset of the EJ (legacy 5sp?) box and a 4.11 front diff along with a 4.11 pinion shaft onto the EJ's VLSD. Using the dual range front casing ofthe gearbox either fitted to a EJ or an EA82t. And then use a custom gearbox crossmemeber to bolt the gearbox into your EA82 car.

 

To change the ratio of the front diff or to fit any other type of center diff/ 4WD engager gear you need to split the casing and pull the pinion shaft out and replace it with the one that matches the back casing.

 

If you don't care about D/R, you can do this alot easier and just use a EJ with a early EJ gearbox with modded crossmemeber and turbo front DOJ cups.

 

Oh, one other thing. The EJ's center diff casing has an output set about 40mm further backwards then the FT4WD and PT4WD, so you will need to shorten the propshaft... Fun fun..

[baccaruda]

I am rather fond of the dual range and would probably put in a PT low gear for S&G. This is a little bit into the future for me though... but this has been a highly educational thread!

[Numbchux]

well, as far as I've been able to tell. there's no advantage of using a forester 5th gear, to using an N/A legacy or EA82 5th. I'm looking for a legacy FWD 5th gear, which is a bit lower still than a legacy AWD one. I'm not sure if they're interchangeable....but I'm going to find out.

 

someone suggested to me that FWD trannies use a small coupler to attach the output shaft to the pinion. and you could actually convert a FWD trans to an AWD trans by pulling that coupler off, and replacing it with a center diff, and the center diff case to go with it. if this is true, I would assume it would be a very safe bet that 5th gear would be swappable, and taller than the forester 5th.

 

you should care about the PT4WD trannies....because you'll need most of their guts to make a sweet tranny out of your FT4WD one

[baccaruda]

so it seems zzz:banana:

[Phizinza]

I wonder how much it would be to ship the EJ D/R casing (just the front, not the rear diff housing) to the US.. That is all the really need, as long as the gears are all the same size on your legacy's vs EA82 D/R. Because you would need the EA82's input shaft (because it's got the special two piece dual range stuff) and you would need the EJ's output shaft and pinion shaft. Then you could either do what I'm doing, or just put the VLSD back in and make it back to a dual range AWD box. This way it will bolt right up to your EJ (if that's what you are using.)

 

Anyone know the ratios of all the gears in the EA82 and Legacy boxes?