Input needed on EA tranny for EJ project.

[s'ko]

I need some input on this.

 

My 2k OBS has a bad case of rod knock and the tranny synchros are bad.

 

So I secured a EJ25 shortblock that I am going to put the EJ22 heads on and build a high compression hybrid EJ motor.

 

To replace the tranny, I originally wanted to go with a D/R 5 spd but I think that with the high comp and increased torque, the FWD would not be enough with my heavy foot.

 

The D/R I have is a n/a one so the stub axles are 23 spline. I have a ft4wd s/r in my garage as well so I decided to take apart both trannys to get the 25 spline stub axles from the FT4wd tranny and put it into the D/R front diff. While I had it apart, I started seeing if the FT4wd main gear set would work in the D/R casing and it fits. Problem is that it would be 3.7 final drive, but then the d/r would be the 1.5 to 1. I also would not have to swap out the 3.7 gearing on the LSD rear diff to 3.9.

 

Should I rebuild the D/R tranny to basically be a RX tranny w/the 1:5 to 1 D/R?

 

Final product of this project is going to be 2k OBS w/2 inch lift and Forester struts. High Compression EJ hybrid motor. Plan on running atleast 27 inch tires.

 

Thanks for the input.

 

BW

Edited April 11, 2009 by s'ko

[Gloyale]

You would need to use the upper shaft from the D/R, and the lower shaft of the FT4wd.

 

Now, problem is, I believe if you count carefully the ratios on 2nd through 5th are slightly different. So I do believe you would have to chose which set you wanted to use and press them off, and onto appropriate shafts for you're swap.

 

I am currently working on a similar project, using an EJ viscous AWD tailsection. I found I need a specific few trannys that came in early imprezas to have the same ratios. Otherwise, I would need to swap gearsets on teh shafts, as mentioned above.

[Numbchux]

You would need to use the upper shaft from the D/R, and the lower shaft of the FT4wd.

 

Now, problem is, I believe if you count carefully the ratios on 2nd through 5th are slightly different. So I do believe you would have to chose which set you wanted to use and press them off, and onto appropriate shafts for you're swap.

 

exactly right.....although, I wouldn't call them "slightly" different.

 

 

it's a fairly complicated project, but I think the results would be worth it.

 

 

actually, i think the best would be the D/R, but with the EJ center diff and pinion. the FT4WD center is more than a little annoying, I don't think the slight improvement in off-road capability (locked vs LSD) is worth the sacrifice in on-road traction (open vs LSD).

 

this would also allow you to use the un-modified EJ driveshaft/linkage (just have to fab something for the hi-lo shifter, but you'd be able to use EJ 5MT linkage....meaning real-live upgrades are a possibility.

Edited April 11, 2009 by Numbchux

[s'ko]

ok. so if i take the FT4wd upper gearset and the D/R upper gearset to a tranny shop & have them swap it, it should be good.

 

i regards to using the EJ center, i will see about getting a trashed EJ tranny w/the center diff. shouldn't be too hard to find. would i have to use the ea casing or can i used the ej casing?

i would ideally like to either buy & use the ej tranny or buy the adapter plate.

 

thanks for the input

BW

[Gloyale]

ok. so if i take the FT4wd upper gearset and the D/R upper gearset to a tranny shop & have them swap it' date=' it should be good.

 

i regards to using the EJ center, i will see about getting a trashed EJ tranny w/the center diff. shouldn't be too hard to find. would i have to use the ea casing or can i used the ej casing?

i would ideally like to either buy & use the ej tranny or buy the adapter plate.

 

thanks for the input

BW[/quote']

 

You would have to machine the EJ case to accept the D/R shaft and shifting mechanism. I think it will be easier to just use an adapter plate. that is my intention when I do my project.

[Numbchux]

adapter plate

EA82 D/R front case halves

EA82 D/R input shaft with EA82 FT4WD drive gears

EA82 FT4WD driven shaft.

EJ center diff and it's housing

EJ pinion (has to match the center diff)

EJ front diff

EJ axle stubs

EJ driveshaft

EJ linkage. done.

 

can't use the center diff/pinion/front diff from your trans? if it's really just a synchro problem, you wouldn't need to buy anything extra.

 

 

if downtime is your concern, you could still assemble the main shafts/gearsets before pulling the EJ out, then just pull the center off, split the case, swap pinion/front diff, assemble the case, assemble the tranny, re-install. I'd be it'd take less time than having a driveshaft modified.

Edited April 12, 2009 by Numbchux

[86ruguy]

I'm Sorry.....ALL I CAN SAY IS .....WOW

[s'ko]

adapter plate

EA82 D/R front case halves

EA82 D/R input shaft with EA82 FT4WD drive gears

EA82 FT4WD driven shaft.

EJ center diff and it's housing

EJ pinion (has to match the center diff)

EJ front diff

EJ axle stubs

EJ driveshaft

EJ linkage. done.

 

can't use the center diff/pinion/front diff from your trans? if it's really just a synchro problem, you wouldn't need to buy anything extra.

 

 

if downtime is your concern, you could still assemble the main shafts/gearsets before pulling the EJ out, then just pull the center off, split the case, swap pinion/front diff, assemble the case, assemble the tranny, re-install. I'd be it'd take less time than having a driveshaft modified.

 

down time is a somewhat of a concern since i only have a 1 car garage & don't have extra space to rebuild a tranny & have the car apart. if i manage to get approved for a home loan, then i will be looking for a 2 car garage and then i will have plenty of room.

how hard is it to remove the gears and install them onto the pinion? is it something i can do at home or do i need a tranny shop to do it?

 

from what you have gathered, your end product will have the lsd center. it there a way to get the lsd stuff into the locking center diff housing?

 

thanks for the input on this project

 

bw

[Gloyale]

adapter plate

EA82 D/R front case halves

EA82 D/R input shaft with EA82 FT4WD drive gears

EA82 FT4WD driven shaft.

EJ center diff and it's housing

EJ pinion (has to match the center diff)

EJ front diff

EJ axle stubs

EJ driveshaft

EJ linkage. done.

 

 

Parts in red are really the same piece, so Whichever driven shaft you use, that will determine the ring and pinion ratio.

[s'ko]

looks like I will have to swap out the rear diff to the 3.7 LSD if I stick w/the FT4WD gearset b/c the DR gearset is not long enough to engage the FT center diff. I will also be going with the locking center as opposed to the LSD EJ center. Decision is mostly based on a space issue. If I can secure a spot that I can leave it for a few weeks, I might go with the LSD center.

What I foresee it being in the immediate future is a family car, primarily wife driven, maybe the occassional desert camping trip and snow driving.

 

If I had time and space, and an extra $1000 lying around, I would do front & rear LSD w/locking center diff. I was looking at an OBX front LSD diff on ebay for less than $400 right now.

[Numbchux]

Parts in red are really the same piece, so Whichever driven shaft you use, that will determine the ring and pinion ratio.

 

they're really not. the pinion shaft is a separate piece from the driven shaft. separating them is not hard at all.

 

I have not been able to get more than just 5th gear off the shafts, even with my el cheapo press. so you may want to have a pro do that....

 

but, you could have the gearsets ready to go, then all you'd have to swap is the pinion and diffs, which do not need a press or anything.

 

 

I could easily do it in less time than the local driveline shop could have my driveshaft modified. so as far as downtime is concerned, I know this would be faster in my case.

 

also, by using the EJ center diff/case extension, the EJ tranny mount bolts right up, so no custom crossmember.

[s'ko]

they're really not. the pinion shaft is a separate piece from the driven shaft. separating them is not hard at all.

 

I have not been able to get more than just 5th gear off the shafts, even with my el cheapo press. so you may want to have a pro do that....

 

but, you could have the gearsets ready to go, then all you'd have to swap is the pinion and diffs, which do not need a press or anything.

 

 

I could easily do it in less time than the local driveline shop could have my driveshaft modified. so as far as downtime is concerned, I know this would be faster in my case.

 

also, by using the EJ center diff/case extension, the EJ tranny mount bolts right up, so no custom crossmember.

 

ok so the pinion is a different piece than the rest of the gear shaft?

How do you seperate it?

 

I hear you on using the EJ casing to eliminate the need for adapting the tranny to the crossmember.

[Numbchux]

yep, FT4WD/AWD driven shafts and pinion shafts are 2 pieces, one inside the other. 27mm nut on the end, and they come apart, pretty easily. no press needed, I think I had to give mine a little tap with a hammer.....but it really was a little tap, no pounding.

 

pics of the one I have in the basement. this is all out of a '93 legacy 4.111 trans.

 

assembled, see the 2 sets of splines on the end? the one on the end is the pinion, the other is the tranny "output" (it drives the center diff).

 

disassembled:

 

 

AFAIK, you can use the driven shaft (the hollow one) from the FT4WD trans (this is why it has to be the FT4WD one, as the PT4WD ones are one piece...), with the EJ pinion through it, and EJ center diff.

 

my only concern is gearing. the EA82t .871 5th gear with anything shorter than a 3.7 diff ratio is going to turn some really high rpms unless you're running big tires (my loyale currently has .871, 3.7, and 26.2" tires, and still turns over 3k rpms at 70 mph. with stock tires, it was almost 4k!)

[Gloyale]

A few differences of note between trans.

 

 

EJ 1-2 shift collar and fork are about an 1/16 of an inch wider than standard D/R EA box.

 

3-4 shift collar has a notch to clear the enlarged Speedo gear section of the Pinion shaft.

 

With a 4.11 ring and pinion installed in the EA D/R case, there is about 1/16 in. negative clearance issue (it hits) between the Hi/Lo shift collar and the very outside edge of the Ring gear teeth.

[Gloyale]

they're really not. the pinion shaft is a separate piece from the driven shaft. separating them is not hard at all.

 

I guess I meant that the actual pinion head was not a seperate piece. It is integral to the configuration of the FT4wd and AWD bowes. So just the actual pinion teeth couldn't be simply swapped onto the EA D/R shaft.

[Numbchux]

I guess I meant that the actual pinion head was not a seperate piece. It is integral to the configuration of the FT4wd and AWD bowes. So just the actual pinion teeth couldn't be simply swapped onto the EA D/R shaft.

 

of course not. but the pinion shaft and driven shaft are very much 2 pieces. I'm talking about using all EA gearsets with the EJ pinion shaft. shift collar/synchro differences are not an issue.

 

and yea, 1.59:1 won't clear 4.111 ring gear without modification, ring gear can be machined down, or a 3.9 will have to be used (or 1.196:1 low). but, like I said, EA82t 5th gear + 4.111 would be miserable on the freeway!!

 

 

 

 

there's no real "easy" answer to all this. but you definitely could get a pretty badass setup with the parts you have.

[s'ko]

of course not. but the pinion shaft and driven shaft are very much 2 pieces. I'm talking about using all EA gearsets with the EJ pinion shaft. shift collar/synchro differences are not an issue.

 

and yea, 1.59:1 won't clear 4.111 ring gear without modification, ring gear can be machined down, or a 3.9 will have to be used (or 1.196:1 low). but, like I said, EA82t 5th gear + 4.111 would be miserable on the freeway!!

 

there's no real "easy" answer to all this. but you definitely could get a pretty badass setup with the parts you have.

 

lots to think about. upper gear set is at a machine shop getting worked on. Charging me $50 to swap the gears out. Sounds reasonable.

 

Thanks for the wealth of knowledge. I am definately going to be kicking this around. might want to condense this thread w/pictures and make it a sticky as I think this is the next frontier in Subaru Retrofitting.

 

So the final dilema is locked center or LSD center.

 

Locked center has better off road characteristics but the open center diff limits overall on road capabilities.

LSD center has better all round characteristics but limited off road

capabilities.

 

Seeing as it's pretty easy to get the pinion shaft swapped out, I am guessing that downtime overall is going to be about 1 day to get the EJ tranny apart and reassembled w/the bits that I want.

 

My biggest fear is getting the thing back together. I am kinda intimidate by how the shifting rod connects to the shifting forks and getting that right.

 

BW

[Numbchux]

So the final dilema is locked center or LSD center.

 

Locked center has better off road characteristics but the open center diff limits overall on road capabilities.

LSD center has better all round characteristics but limited off road

capabilities.

 

well' date=' just to throw a monkey wrench in that. the center LSD is pretty damn strong. When Austin and I went wheeling up here in MN a few years ago, he got high-centered in his impreza. both rear wheels on the ground, with quite a bit of weight on them, but the fronts were in the air. he was still able to dig a hole in the back....IMHO, if you're not going to weld the rear, you won't need the locked center.

 

the center diff is pretty much my biggest frustration with my loyale. the full-locked center induces understeer at RallyX and ice racing tracks (can't use the e-brake for tight turns either), and the open diff just allows lots of front wheelspin on AutoX courses.

 

Seeing as it's pretty easy to get the pinion shaft swapped out' date=' I am guessing that downtime overall is going to be about 1 day to get the EJ tranny apart and reassembled w/the bits that I want.[/quote']

 

I think that's about right. will take some tinkering, but I think it's totally doable.

 

My biggest fear is getting the thing back together. I am kinda intimidate by how the shifting rod connects to the shifting forks and getting that right.

 

BW

 

agreed....my next project (when my EJ trans gets here) is to pull it apart and swap the 5th gear for the tallest ratio I can find (WRX), hoping for awesome freeway gears too. I'm more than a little nervous about tearing into a tranny

[Gloyale]

and yea, 1.59:1 won't clear 4.111 ring gear without modification, ring gear can be machined down, or a 3.9 will have to be used (or 1.196:1 low). but, like I said, EA82t 5th gear + 4.111 would be miserable on the freeway!!

 

 

I was worried about machining down the ring gear. Seems the outside edge is the leading part of the tooth face as the car goes forward. I suppose if it was done with precision.zzz:Flame:

 

 

As far as final gearing, I'm planning on Standard EA82 5th gear, 4.11..........pushing 235/75/15 Maxxis Bighorns:grin:

[Numbchux]

I was worried about machining down the ring gear. Seems the outside edge is the leading part of the tooth face as the car goes forward. I suppose if it was done with precision.zzz:Flame:

 

 

As far as final gearing, I'm planning on Standard EA82 5th gear, 4.11..........pushing 235/75/15 Maxxis Bighorns:grin:

 

I hear they machine them down over in Oz.....

 

and yea, your ratios should be fine.

[Gloyale]

I hear they machine them down over in Oz.....

 

and yea, your ratios should be fine.

 

Yeah, they can be machined. In fact if you look at the 3.9 ring gear fromt he D/R it is beveled at the edge to clear the D/R gears.

 

Problem is, they machine it BEFORE hardening the steel.

 

I had a good machinist here try it, and he got about .150" before his tool started deflecting against the teeth. Good news is, that may be enough if we also take about .050 off of the D/R shift collar.