5 speed dual range gearing

[iluvdrt]

OK, so after my lift and new tires (215/75/15 BFG AT KO 2's on Method Race wheels) on my 82 Brat my gearing is horrible (to be expected, currently running 3.9's). I contacted Subieworks about changing the gear ratios in my 5 speed dual range. He says he remembers doing it and that it can be done. I have searched all over AU Subaru and it seems they typically do this in the EJ 5 speed dual ranges that are available there, but I haven't seen anyone do it in a EA 5 speed dual range.

 

So my question;  Has anyone installed 4.11's or 4.44 gears into a EA 5 speed dual range? Ideally, I would like 4.44, but I know the ring gear crown will have to be machined quite a lot (if possible), whereas the 4.11 would not need as much machining thus being a little stronger.

 

No, I do not want to EJ motor swap it (yet). In my experience, adding more power to compensate for under gearing is not the right way to do things. Id rather have the correct gearing which would be beneficial no matter how you look at it. I also know some of this work will be expensive and considering I already have over $5000 into my Brat (excluding the purchase price), I am not concerned with the cost, so please don't mention it.

 

My other option is to have Subieworks import an EJ dual range with 4.11 gears and swap the low range gear of the EA82 5 speed box into it. Id rather not do this because than Ill also be needing an adapter plate as well as flywheel machining. If I were to do that, I might as well swap an entire EJ drivetrain into my Brat.    

 

Lots of work and money for a truck that hardly ever goes off road, but its fun and something for me to do. Thanks for your thoughts.

[Numbchux]

EA81 transmissions are VERY different from EA82 and EJ ones. AFAIK, there are no other gearing options for the EA81.

 

EJ Dual range will not bolt to your EA81 engine. So the only way to do that is to do the EJ swap anyway.

 

To return your car to the same rpm range as stock, you would need about a 4.7:1 axle ratio...

 

 

 

 

4.444 is the lowest ratio available. Only way (without serious custom fabrication) to get 4.444s and 1.59:1 low with an EA81 is a pretty considerable frankentrans.....here's the recipe.

 

'87-'89 Subaru RX FT4WD Dual Range transmission

4.444 5MT EJ front ring and pinion (not very common used, but not super expensive from Subaru. 38100AB681)

Any EJ center diff and housing (phase 1 or phase 2. There is a super strong Group N center diff available for the Phase 2 housing. Also 5MT DCCD setups would work. no, no factory 4WD setup will work without serious fabbing)

'85-'89 Subaru GL PT4WD non-turbo Dual range transmission low range gearset and axle stubs (or convert your EA81 axles to 25-spline)

EA82/XT6 clutch/flywheel/starter

Lengthened Ea81 driveshaft (I think, IIRC the EA82 trans is quite a bit shorter than the EA81, and the EJ rear housing is a bit longer...)

EJ transmission mount (since it bolts to the center diff housing)

Crossmember modification for said mount

4.444 rear diff (much more common than the front R&P, since it can come from an automatic car, but will require some custom work to mate with axles)

Customized EJ shift linkage

 

The RX box (as with any EA82t) uses a much shorter 5th gear, even than the 4th gear in the Ea81 4MT. You may want to swap for the standard EA82 5th gear.....you will want to do considerable research on that. I have at least a couple threads around talking about these gear ratio differences.

 

That can all be done, I'm "in the process" (I have been for probably 4 years) of building that exact combination for my Brat. FYI, a Carbonetic front LSD for a WRX will bolt into an EA82 5MT transmission, but will not clear 1.59 low range, not at all. I've made zero progress since that discovery.

 

 

 

I happened to have an RX donor box. But they can be hard to get your hands on. It might be easier to get an EJ D/R donor box, in which case, you'd only need the 4.444 R&P, 1.59/23 spline stub donor box, and the external parts for the installation. Then do the EJ swap while you're at it, you'll get the benefits of the EJ swap, and MUUUCH better clutch options. Not to mention no need for an adapter plate.

[iluvdrt]

I already have the EA82 5 speed installed and fully operational with all supporting mods that had to be done.

 

From everything I have read on AU Subaru and talking to Chris at SUbieworks, the EA82 5 speed only needs the ring gears machined and the pinion shaft shortened fit

 

I think it may be better to go with the EJ dual range, 1.59 low range (its been done a hundred times over) and just get the adapter plate to mate the EA engine and EJ Trans together. Or just bite the bullet and do a complete EJ swap with DR EJ box.

 

hmm decisions....

Edited March 9, 2016 by iluvdrt

[Numbchux]

I already have the EA82 5 speed installed and fully operational with all supporting mods that had to be done.

 

From everything I have read on AU Subaru and talking to Chris at SUbieworks, the EA82 5 speed only needs the ring gears machined and the pinion shaft shortened fit

 

I think it may be better to go with the EJ dual range, 1.59 low range (its been done a hundred times over) and just get the adapter plate to mate the EA engine and EJ Trans together. Or just bite the bullet and do a complete EJ swap with DR EJ box.

 

hmm decisions....

 

OK, I've actually test-fitted a 4.444 x 1.59 transmission with an EA bellhousing. If I hadn't spent so much time and money on using that Carbonetic diff, it would be in my Brat. I've run EJ internals in an XT6 case in my '88 XT6.

 

FT4WD EA82 pinion shaft is considerably longer than an EJ one. So it would have to be lengthened. It's been discussed on here that it is theoretically possible to cut them both, and weld them together, but that's some seriously precision fab work, in a crucial part of the car. I wouldn't run it....

 

Here's some comparison shots of the 2:

http://www.ultimatesubaru.org/forum/topic/129898-4444-x-1592-x-3545-251/?do=findComment&comment=1104016

 

PT4WD EA82 pinion shaft is not a separate piece from the transmission output shaft, and only leaves one set of output splines to the transfer housing. I haven't had one of those apart, so I don't know exactly how that all interfaces with the transfer mechanism, but it's a pretty significant change in design....

 

 

The available adapter plates are for putting an EJ engine to an EA transmission. It will not work the same the other way (EJ transmission bellhousing is deeper, so adding an adapter plate means the input shaft is now several inches too short).

[skishop69]

We have actually built 411 and 444 EA82 tranny's. Someone else here took the time and the money to have it done. Shawn and I paid for the 'rights' to the manual that shows step by step how it was done and exactly what parts and years will work. Since then, I've discovered there are other tranny parts that can be substituted. This recipe is a bolt together application with NO fabbing required except for having to shave the 444 ring gear a smidge to fit. Unfortunately, because of our agreement, I can't give you the specific info.

 

Yes, you can dump EJ internals into and EA82 box, but IT WILL NOT LAST. The tolerances are different and will cause excessive wear, binding and ultimately failure. I've taken the measurements. It won't last and it's not DR.

 

You can't weld input shafts together and have it work. The torsional shearing force applied to the shaft in low range if you were to ACTUALLY be wheeling and had to apply significant throttle when stuck or climbing rocks, would twist and break the shaft in short order. Performing such a weld would require bevelling, multiple passes, a custom alignment jig, a mill, a lathe and the ability to true the shaft when all is said and done, because it's going to warp. If it is not true or out of balance and spinning at 2000 RPM or higher, you'll get a vibration and eventually damage the clutch, the input bearings and quite possibly the rear main bearing and seal. Welding the two pieces will destroy the tempering of the factory pieces weakening them so if the weld doesn't snap, the shaft will.

 

All that being said, you can start experimenting like Numbchux is doing or do the old Nissan divorced t-case mod if you have good fabbing skills and can actually locate an old Nissan divorced t-case.

[WoodsWagon]

What about an EA 4eat with a later 4.44 ring and pinion? With a good cooler the torque converter can make up for much of the lack of gearing.

[D3F0]

I am loving the info in this thread its too bad some of the info cant be shared.

[iluvdrt]

I agree. Sucks it cannot be shared. I mean what is the point in withholding the info? It's not like these cars will ever be mainstream, or anyone will get rich from doing dual range gearing conversions lol.

 

As much as I don't want to do it, I think the best option is to keep the dual range and just do a EJ22 swap. I need to work out the front suspension first. My springs are shot.

[D3F0]

I am going to swap the locking center diff onto a legacy tranny for my ej20 swap instead of using a adapter plate. Poor mans DCCD thats the only trick I know when it comes to these transmissions. 

Edited March 15, 2016 by D3F0

[Numbchux]

I am going to swap the locking center diff onto a legacy tranny for my ej20 swap instead of using a adapter plate. Poor mans DCCD thats the only trick I know when it comes to these transmissions. 

 

Don't bother. The VLSD is much better. Certainly not worth the work. Especially since I've seen 5MT DCCD assemblies for $500, which means you wouldn't have to open the front of the trans to swap the ring and pinion

[D3F0]

I've heard the other way around its a full lock vs VLSD that do not last long. Ive read that after a full hard and powerful launches the diff pretty much turns into an open diff. Making 1 tire fires up front and losing a lot of overall torque to that wheel.  I am going to put at least 250WHP down so because of that I heard it just weakens the VLSD buy a bunch. The main point of building those two transmissions together is to get rid of the need for an adapter plate for my swap. That saves me 200 dollars and I already have wrx clutches laying around so again another 260 saved.  I already have both transmissions so I am going to build that for free. In the end you are right about the 500 to 600 dollar 5MT DCCD assemblies though I will swap to that once I break everything. Also like the original post I would like to install better gears into the built tranny and this is a good way to get some experience under my belt. Play with what I already have with my Subaru technician buddy. I also eventually what a 4.44 final drive ratio so I can get this thing moving properly. But I am going to just get rid of the RX dual range tranny all together because I know its not good for over 200 hp. I will use a 4.44 forester transmission with an aftermarket Front LSD and some type of Center diff lock. to keep all four wheels truly spinning so i can get this thing to really eat in the corners. 

[Numbchux]

I've heard the other way around its a full lock vs VLSD that do not last long. Ive read that after a full hard and powerful launches the diff pretty much turns into an open diff. Making 1 tire fires up front and losing a lot of overall torque to that wheel.  I am going to put at least 250WHP down so because of that I heard it just weakens the VLSD buy a bunch. The main point of building those two transmissions together is to get rid of the need for an adapter plate for my swap. That saves me 200 dollars and I already have wrx clutches laying around so again another 260 saved.  I already have both transmissions so I am going to build that for free. In the end you are right about the 500 to 600 dollar 5MT DCCD assemblies though I will swap to that once I break everything. Also like the original post I would like to install better gears into the built tranny and this is a good way to get some experience under my belt. Play with what I already have with my Subaru technician buddy. I also eventually what a 4.44 final drive ratio so I can get this thing moving properly. But I am going to just get rid of the RX dual range tranny all together because I know its not good for over 200 hp. I will use a 4.44 forester transmission with an aftermarket Front LSD and some type of Center diff lock. to keep all four wheels truly spinning so i can get this thing to really eat in the corners. 

 

Well, sounds like you already know everything.

 

Good luck!

[D3F0]

No i do not! haha I am going by what I have researched for the last few years. There are still a few unknowns but yes I am pretty familiar with it it all. The RX Dual speed box though I am still looking  through threads like this to see if it can be strengthened cheaply. My ultimate goal would be for sti power with high and low and dead reliable. But I need that secret recipe above. HOW MUCH GUYS!?