Jump to content
Ultimate Subaru Message Board

4.11 dual range please!!


awesomedude
 Share

Recommended Posts

Ok guys this is my first post and i hope that i can get an answer as i cant seem to piece together all the info i have found so far.Basically what i want to know is if i can possibly get 4.11 or lower in my 88 d/r gearbox.I know that the legact ring and carrier fit in the box but has anyone adapted a pinion shaft from an overseas 4.11 dual range or 4.44 ideally.I really dont car if i have to do some fancy fabricating or get some machine work done,i just need lower than the 3.90's ive got.My car goes great i just want a little extra on the road since i'm running 27 ssr's,it will also help me off road in the hilly stuff:)

 

 

And here is the car awaiting this wonderfull(potential) modification.

 

http://s120.photobucket.com/albums/o199/znut_2007/?action=view&current=000.jpg

Link to comment
Share on other sites

well its a yes and no answer it is buildable but you will need a 80's EA 5spd hi/lo 4x4 trans (not AWD) and a 90's EJ 4.11 5speed AWD you will need from the EA trans

 

1) front half of the case

2) hi/low gears

3) all shifting gears

4) top shaft + reverse

 

EJ trans

1) rear AWD case

2) rear AWD diff + transfer gears

3) 4.11 ring and pinion with front diff

 

the problem is making all the parts fit together properly and not have it blow up :dead:

 

you will have to remove all the gears off of the 3.90 pinion shaft and press them all back on the 4.11 pinion , reinstall it in the hi/lo case reset all the preloads, the final trick is that the 4.11 pinion shaft is a diffrent lenth then the 3.90 and you have to use the AWD rear diff and out put shaft transfer gears , making an AWD EA 4.11 hi/lo 5speed .

 

AND NO you cant use the RX diff lock AWD tail shaft that has a diffrent pinion shaft lenth as well .

 

This tranny would make a horable off road tranny if you get one weel in the air gess what all the power is going to one wheel , or break an axel and you are stuck ! you are thinking better limited slip! 800$ and you will burn it out the first time you break an axel $$$$ ,

 

SO my solution is to weld the center diff making it constant 4x4 but this will make it almost undrivable on pavment and parking lots hell .

 

BUT if you got the time and two trannys you are willing to sacrifice too the SUBARU gods if all goes bad ! and only have a trail rig it can happen .

 

but there may be a unicorn tranny out there that has a 4.11 pinion shaft lenth the same as the 3.90 hi/lo but i have yet to see it !

 

I sorta went on a rant sorry! but i have like 5 trannys apart RX hi/lo, reg. hi/lo , EJ, RS, and WRX trying to see what will work and that is what i have come up with . :grin: i just havent had the time to built this crazy tranny , but my solution was to just EJ my hatch and make torq at 500 rpm :banana:

Link to comment
Share on other sites

but there may be a unicorn tranny out there that has a 4.11 pinion shaft lenth the same as the 3.90 hi/lo but i have yet to see it !

 

I don't think it exists....but it could definitely be made (but probably not for cheap).

 

 

as mentioned, the only way to do it without using a custom made pinion shaft, is to use the EJ-series center diff (which means no center locker!).

 

you'd have to sacrifice at least 2 trannies....maybe 3 (it's possible that the PT4WD pinion is not removable from the output shaft in the trans. maning you'd need the output shaft from a FT4WD trans, but those only have the 1.196 low range, which would defeat the purpose of the whole thing.....so you'd have to sacrifice a PT4WD DR trans for the 1.592 low range gearset........). and all only for a final crawl ratio change from the stock 22:1 up to a 23.2:1.

 

 

 

not at all worth it.....IMO

 

 

 

you will have to remove all the gears off of the 3.90 pinion shaft and press them all back on the 4.11 pinion

 

this, however, is not true. the pinion shaft is quite easily removed from the output shaft, just need a vice, an impact wrench, and a 27mm socket. assuming, as previously mentioned, that they're separable on a PT4WD box....

Link to comment
Share on other sites

your better off just going with a divorced case option and get a set of ea71 4.11 rear diffs. much easier, cheaper and works. did i mention i have a car with that setup for sale within the next month or two... or as soon as i get a set of matching 30 or 31 m/t tires.

 

Yup;)

See both our rigs in the Photo Gallery :headbang:

Link to comment
Share on other sites

so lets see here, i looked into the custom pinions a few years ago... and your talking about a mere 22:1 or 23:1 instead of 20:1 (which isn't even enough to compensate for the tires...) and shelling out 10k for developement. or less than a grand and add another tcase. turbone and i have about 60:1 crawl... hmm.... lets see here. lot of money or headache for nothing, or actually get something... not to mention you can use an lsd up front like mine has with a divorced case...

Link to comment
Share on other sites

Suck!! lol-i was really hoping this would be much easier.

 

So what is the verdict concerning trannies from austrailia or europe.Arent those later model dual range boxes 4x4 or are they in fact just the high low AWD that was mentioned earlier.If they hace the center lock on those than that would fit in our boxes with our gearing no?If not i guess its time to either EJ it or start researching the t-case deal:rolleyes:

Link to comment
Share on other sites

Suck!! lol-i was really hoping this would be much easier.

 

So what is the verdict concerning trannies from austrailia or europe.Arent those later model dual range boxes 4x4 or are they in fact just the high low AWD that was mentioned earlier.If they hace the center lock on those than that would fit in our boxes with our gearing no?If not i guess its time to either EJ it or start researching the t-case deal:rolleyes:

 

only thing unique about those, are the bellhousings. they have the same EJ non-locking center diff as any other EJ AWD box.

Link to comment
Share on other sites

Sorry, no time to read anything but the first post. So heres my input on the first post.

 

The only way to get a semi bolt together D/R with 1.59 to 1 low range with a 4.11 is to use a EJ D/R box which you need to source from Australia, install the EA82 low range (pretty easy.) But because of the pinion shaft design on the different gearboxes you WILL have to use a VLSD center differential. You cannot use a FT4WD diff lock box with a EJ pinion (it will not work.) AlsoI believe the teeth on the 4.11 crown wheel need grinding to fit in with the 1.59 to 1 low. The 4.44 would be much worse I believe.

 

So, a few facts

FT4WD boxes came in 3.7 ratio, and the XT's had 3.9, only they are S/R so you would need some shaft swapping.

FT4WD boxes have a pinion shaft going through the output gearset like the EJ's do, only they are not interchangable with the EJ version as the center diff is 100% different design.

PT4WD boxes don't have a seperate pinion shaft, its part of the gear shaft and that is why you can't use PT ratios on FT or AWD boxes.

1.59 to 1 low gears will not fit right into the boxes that came with 1.19 ratio, you need to swap the shift fork and that requires some drilling and maybe welding depending on if you use the detent or not.

EJ rear casing (diff center casing) is about 40mm longer so your propshaft needs to be shortened.

EJ rear casing cannot hold FT4WD center diff.

 

Ok, well theres a bunch of random usefullish info..

Hope it helped.

Link to comment
Share on other sites

ok well heres my next question lol.I am wondering if it seems possible(i know it seems so...but) to do some machine work to two of the needed pinions(legacy and ea d/r) and graft the pinion end of the leagacy shaft onto the original d/r shaft,after which they could be drilled and pinned(also welded in) and then tig weld the seam.I think considering the torque put out by these motors that would be more than enough but i could be wrong,perhaps two or more pins would be better.Of course everything would have to be straight and and the graft would have to be done in an unused are of the shaft,or at least where you could get away with it(possibly the weld could be built up and then machined down to spec after?).I realize this borders on a custom made pinion but this has to be cheaper than that,plus its still all subaru!! :)

 

 

Oh and heres a crappy paint program drawing i made to help visualize.

 

http://s120.photobucket.com/albums/o199/znut_2007/?action=view&current=pinion.jpg

Link to comment
Share on other sites

There is a guy in Australia currently trying to get that done.. don't know if it will work or not. You need VERY HIGH precision when doing something like that. And it will need heat treatment afterwards of cause.

I really doubt the pin method it looks like you have drawn would be anywhere near strong enough.

Link to comment
Share on other sites

the fabrication would need to be incredibly precise. and I just don't think the cost required would justify the minimal gains :rolleyes:

Kinda totally sums it up for me.

I've just got FT4WD with centre diff lock, 1.59:1 low, 3.7 diffs, in a EJ D/R case so it bolts right upto the EJ22 engine. I'm happy with it, could do with some lower gears, but the rear locker should make it so I don't have any trouble with the terrain I want to drive over.

Link to comment
Share on other sites

ok well heres my next question lol.I am wondering if it seems possible(i know it seems so...but) to do some machine work to two of the needed pinions(legacy and ea d/r) and graft the pinion end of the leagacy shaft onto the original d/r shaft,after which they could be drilled and pinned(also welded in) and then tig weld the seam.I think considering the torque put out by these motors that would be more than enough but i could be wrong,perhaps two or more pins would be better.Of course everything would have to be straight and and the graft would have to be done in an unused are of the shaft,or at least where you could get away with it(possibly the weld could be built up and then machined down to spec after?).I realize this borders on a custom made pinion but this has to be cheaper than that,plus its still all subaru!! :)

http://s120.photobucket.com/albums/o199/znut_2007/?action=view&current=pinion.jpg

 

 

This could potentially work, if you had the expertise to do it or the money to pay someone else to do it.

The pinning method you show in your drawing would not hold up. You'd want to have at least one longitudinal key, or preferably multiple splines. I suspect the pinion shafts are hardened, so cutting internal splines in the 4:11 pinion would entail some tricky machining (and expensive if you were paying someone to do it). Even then, cut splines are nowhere near as strong as rolled splines, so weather it would hold up would be a question. It would be best to do no welding on the part so as to not alter it's heat-treatment- otherwise it would probably just twist off at the weld the first time you took it out. You could maybe hold the pinion gear on the shaft with a large bolt into the end of the shaft, but that seems a little iffy to me (and internal threads in a hardened shaft is not a fun job). I'd probably press it on with an interference/shrink fit- that's how we put locomotive wheels and gears on the axles, and they stay put.

You also have to deal with the fact that the 4:11 and 4:44 ring gears interfere with the high/low gearing because they are bigger in diameter than the 3:90 (I have heard this, anyway).

Basically, it would be a very long experimental process, probably with a tranny or two trashed in the process. I have thought about doing it (I have all the equipment to do the machine work) but have so many other projects that it will probably never get done.

Andy

Link to comment
Share on other sites

I don't know.

This all looks doable if you are made of $$. (when I win the lotto I'll have a machine shop whip us up a bunch of custom lower gearsets...... :rolleyes: )

Guess when the time comes for big tires and a lift I'm just gonna put an extra diff under the front and a tranfer case. Been done before so the hard part of figuring it all out has been done by others already. :)

Just my 2 cents.

Was really hoping for a simple swap type mod here though. Kinda knew that would be too easy.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...