Lexus A340E to 4WD?

[Chewy]

Ok, I'm trying to tackle yet another aspect of my 1UZ swap...
In addition to the installing the motor, I decided that I should complete my 4WD conversion at the same time.  Or at the very least, install just the front differential so that when I place the 1UZ into the engine bay, the position is correct for when I complete the 4WD conversion later down the road.

Anyway, I had some questions regarding the transmission and transfercase.  I was planning on using the Lexus 340E transmission for the same reasons Cebby wanted to - primarily to make sure the tranny and ECU would "talk" to each other.  I'd decided the best way to accomplish this is to use Inchworm's Pre-Runner adapter.  But I remembered reading that adapter was designed for RH-drop gear driven cases.  And after speaking with Jim, he confirmed it.  So for my 3rd Gen 4Runner, I'd have to additionally buy their "Lefty" transfer case...a bargain at $2000!!!  Needless to say, I don't know if I want to spend that much.  I asked about using a stock, LH-drop chain drive case but was told that that setup wouldn't work since there are no provisions to mount the transfer case to the transmission cross-beam.

So here are my questions...

From what I've read, it seems the biggest issue of trying to simply remove the 2WD tailhousing from the Lexus tranny, bolting on a 4WD tailhousing, and then connecting a stock transfercase would be the Lexus output shaft being too short, right?  But after looking at the following photos, it seems like the shaft might be long enough.  I dunno...how long is a 4WD tailhousing?

(borrowed this from SAR Squid on TTORA)  Picture of a Tacoma 2WD tranny with tailhousing removed...Lexus tranny is same length output shaft.  Would have to cut off the threading, but still looks like the output shaft would go into the 4WD tailhousing a good several inches...


Photo of a transfercase from a 97 4Runner Limited.  Looks like the input coupler would go into the 4WD tailhousing by a few inches...


So what am I missing here?  How far does the tranny output shaft normally go into the transfercase?  If I do need a longer output shaft, do you guys think this would work...
-Measure how long a shaft is needed to properly connect transfercase to tranny
-Get a 23-spline shaft and a coupler
-Cut shaft to correct length
-Slide coupler over end of Lexus output shaft
-Insert splined shaft into coupler and other end into transfercase

Voila?  Or am I missing something else?

Also, in the photo of the transfercase above, is that strictly a "mechanical" case?  Meaning no shift-on-the-fly, ADD, etc?  I compared it to the photo Cebby has of the case attached to his '00 A340F.  That one seems much longer & complex than this one.  This case however is apparently from a 99 4Runner SR5 which I thought for sure had ADD, etc.  Any insight?

[toyminator]

Here are some pics.  The 1st one is of the Lexus A340E and the 4Runner A340F side by side.   The other is the A340F looking into the 4wd adapter.  If your are going to use the Lexus tranny I think you will actually need to cut off some of that spline.  I not quite sure as I will be using the pre-runner adapter for mine.   If your not afraid of  taking apart the tranny you can use the whole output shaft from an A340F and put it in the Lexus tranny.

[Chewy]

Thanks for the photos; it helps trying to visualize everything!  So if I'm looking at this correctly, if I were to take the Lexus transmission...cut down the splined output shaft to the proper length (or replace it with one from an 340F)...connect a 4WD tailhousing...then bolt on a transfercase...that's all it would take, right?

I found these pics after digging around on TTORA...
Rear of 340E...


Rear of 340F...


They said the differences between the 340F and 340E were "the 4x4 has a larger oil pan, shorter output shaft, and a lot more oil passages than the 2WD."  Do you think not having the bottom "cutouts" on the Lexus tranny could present a potential issue with cooling?

More questions!
-Is there a difference in transfercases from those that came from an Auto versus those from a Manual?
-From the look of the 4WD tailshaft, it seems like there's an oil seal in the middle.  Is it correct that ATF does not flow past this?

[toyminator]

I have heard that the Lexus tranny has bigger clutch packs but I have not seen this for myself.  I do not know if the tcase is the same on 5spd's as it is on Autos.  The passages shouldn't be an issue becaue you want the fluid to stop there anyway.   The transfer case uses gearl oil.  In fact.  the Lexus transmission may be better that is has those passages blocked because you don't want all the fluid running to the back of the tranny on steep inclines.   That is the reason that the older Pickup/4Runner 1985-1995 A340H models are not good doners.  They share fluid with the tcase and have problems with fluid running into the transfer case on steep inclines robbing the tranny of fluid.

[76ANTHONY]

im watchin this thread clooooose, i wanna see if i can use a lexus trans for my swap in my 1990runner 3.0 auto 4x4......sure would be nice to have a trans that will hold the power and not take a dump...and makes the wiring easier too

[blackrunner91]

Okay, I went the route that you are going.  I don't have my 4Runner finished yet, but I see no reason it's not going to work.  Everything is pretty much plug and play.  Just measure the length of output shaft that you are going to need and then cut the output shaft on the lexus trans.  Then you will have to drill the case of the adapter to use another speed sensor.  The lexus has 2 of them.  The one that needs to be relocated is the one that is on the tailhousing of the lexus.  Anyways, it will be used with the 4 point star on the lexus transmission output shaft. Just cut it in half between the worm gear and the star.  Just leave enough space to drill and tap for a set-screw to hold it up on the shaft.  I'm probably forgetting something.

[Chewy]

Are you talking about the 3-pin sensor on the right side of the Lex tranny?  Isn't that the one that's normally found on the transfercase in 4WD vehicles?

Yeah, I really don't see why this set-up wouldn't work!!  I still need to get my hands on a 4WD tailhousing and transfercase, that way I can physically "see" how it all mates up (fingers crossed!!)  Gonna need some help with the output shaft though...anyone got an accurate measurement of the 4WD shaft??  

Hey, 76ANTHONY...As for using the Lex tranny with earlier, gear-driven transfer cases...I don't know if the bolt patterns are the same between the tailhousing and case.  Actually, I'm pretty sure they're not; otherwise I would've just used Inchworm's Pre-Runner Adapter! (designed for those older cases)

[Cebby]

As far as I know, the A34#x cases are the same.  The tailhousing patterns should be the same for all.  I have both - I'll verify this when I get a chance.

[76ANTHONY]

thanks cebby

[76ANTHONY]

Are you talking about the 3-pin sensor on the right side of the Lex tranny?  Isn't that the one that's normally found on the transfercase in 4WD vehicles?

Yeah, I really don't see why this set-up wouldn't work!!  I still need to get my hands on a 4WD tailhousing and transfercase, that way I can physically "see" how it all mates up (fingers crossed!!)  Gonna need some help with the output shaft though...anyone got an accurate measurement of the 4WD shaft??  

Hey, 76ANTHONY...As for using the Lex tranny with earlier, gear-driven transfer cases...I don't know if the bolt patterns are the same between the tailhousing and case.  Actually, I'm pretty sure they're not; otherwise I would've just used Inchworm's Pre-Runner Adapter! (designed for those older cases)

theres still gotta be a way to use all the stock stuff and jam a 1uz in there, im needin ta hit a wrecking yard out here and see whats up.....

[Chewy]

Oh happy day!  I went to the local "U-pull" today and as luck would have it, they had a 97 4Runner!!  As I was combing it over, I found the transfercase already removed, discarded by a previous "vulture" who took the tranny (rats!)  I inspected it and took note of whether it had the actuator motor for

[76ANTHONY]

Are you talking about the 3-pin sensor on the right side of the Lex tranny?  Isn't that the one that's normally found on the transfercase in 4WD vehicles?

Yeah, I really don't see why this set-up wouldn't work!!  I still need to get my hands on a 4WD tailhousing and transfercase, that way I can physically "see" how it all mates up (fingers crossed!!)  Gonna need some help with the output shaft though...anyone got an accurate measurement of the 4WD shaft??  

Hey, 76ANTHONY...As for using the Lex tranny with earlier, gear-driven transfer cases...I don't know if the bolt patterns are the same between the tailhousing and case.  Actually, I'm pretty sure they're not; otherwise I would've just used Inchworm's Pre-Runner Adapter! (designed for those older cases)

so does this mean i cant use the lexus trans, or does it mean i need to buy the adapter, i really dont want to switch to a lefty front driveshaft, i like my righty
has there been any updates on this subject yet, im holdin off buying my engine because of the transmission thing....

[Chewy]

76,
Take a look at Inchworm's "Tacoma Transmission Adapter" http://www.inchwormgear.com/store/product_info.php?cPath=21_38&products_id=73  If I'm understanding it correctly, you can use this to mount an older, gear-driven transfercase up to a Tacoma transmission (A340F).  In order to make it all work, you'll still need to shorten the output shaft on the Lexus tranny and then bolt up a 4WD tail housing (aka "transfercase adapter") from an A340F.  The Inchworm adapter would then bolt to the tail housing and then you'll be able to bolt up your gear-driven transfercase.  Best thing to do is give Jim a call at Inchworm and talk to him.  He's one smart dude when it comes to this...

I'm still trying to locate a 4WD tailhousing for my Lexus tranny, but I may go the same route as Cebby and use a 340F transmission instead.  Only reason is because I found a cheap 340F locally.

[Cebby]

Chewy -

I'm in the process of rethinking my tranny.  With the hoops needing to be jumped through to make the A340f work with the ECU, I am taking a look at doing the output side swap on the A341e instead.  I want to dive into both trannies and see if there is any truth to the claim that the clutches are heavier duty in the A341e.

[toyminator]

76,
Take a look at Inchworm's "Tacoma Transmission Adapter" http://www.inchwormgear.com/store/product_info.php?cPath=21_38&products_id=73  If I'm understanding it correctly, you can use this to mount an older, gear-driven transfercase up to a Tacoma transmission (A340F).  In order to make it all work, you'll still need to shorten the output shaft on the Lexus tranny and then bolt up a 4WD tail housing (aka "transfercase adapter") from an A340F.  The Inchworm adapter would then bolt to the tail housing and then you'll be able to bolt up your gear-driven transfercase.  Best thing to do is give Jim a call at Inchworm and talk to him.  He's one smart dude when it comes to this...

I'm still trying to locate a 4WD tailhousing for my Lexus tranny, but I may go the same route as Cebby and use a 340F transmission instead.  Only reason is because I found a cheap 340F locally.

If you get the prerunner adapter form Inchworm you don't need the 4wd output as it is designed to bolt staight to the back or the transmission housing. 

http://www.inchwormgear.com/store/product_info.php?products_id=995