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Aw4 power handling/ reliablity and performance upgrades.

The replacement sprags I purchased for the A340e are the same part number as the ones I bought for the AW4. In fact, only one of the clutch packs is different. There is no HD sprag for either, which is fine, cause they aren't necessary. Everything I've experienced indicates that proper valve body modifications are all that is really needed. Blue frictions are also a waste of money in this application. Regular raybestos yellows and normal sprags are used in the same transmissions that are running 8.8 quarters in a 3100 lb Supra. I didn't do any of this with BL either, since they don't actually do anything. I went to the man they send the transmissions to. This same guy made my hybrid trans. He and I agreed to trace out the AW4 valve body and map out the adjustments, but we've both been super busy and haven't done that yet. BL charges what they do for a soft rebuild, new OEM sprags, billet piston, and valve body mods. Turns out it's not as magical as some would have us believe. The AW4/A340e is just a damn good transmission, and a few adjustments make it better.
 
After reading through here, I went and adjusted my kickdown cable out of curiosity. Puts some pep back in it's step for sure... So naturally I went off the deep end and adjusted it as far as I could. The 2-3 shift was dang exciting even at no where near WOT! Figure that is a good way to break something so I changed it back. :/
 
Has anyone thought if swapping out the AW4 for the A340 E? From what I understand is all that would have to be done is change out the bellhousing and the tail shaft / 4x4 adapter.

Is this possible?
 
As I understand, the lexus torque converter and bellhousing would be needed to mount the A340e to the Jeep 4.0. I know for a fact that the A340e can be modified using AW4 components so that it plugs directly into the Jeep transfer case (NP231). Electronically they are very different.

Exhibit "A":

Jeep22HybridTransmission7.jpg
 
So I guess the best option would be to swap out the internals between the AW4 and the A340 E. I guess I will have to read deeper into the more technical maters of this conversation.

So, swap out---

1. Srpags

2. Clutches

3. Valvebody
 
Nope.

Can not swap valve bodies. Sprags are the same. One clutch basket takes different frictions. I still do not have a shifter solution yet. (They are shifted on opposite sides)

You need to change hard parts if you want the A340e in your Jeep. output shaft, rear planetary, and whatever else is associated with that, allowing you to install the 4WD adapter housing onto the A340e transmission case.
 
I guess it is an easier swap AW4 parts into the A340E, than the other way around. So they are electronically different? How so? As for swapping in the "hard parts" the only other major complication would be the shifter. Shifted on opposite sides does not sound that hard to fix. Just run a longer shift cable. Would this work?

A lot of thought going into this. I am diving into a new subject for me--transmissions. It is interesting.

If these two transmissions are so "similar", then why do they seem so different?

As for "beefing up" the AW4, I think I would rather just go with the performance kit from Import Performance.


I am putting a 4.9 Stroker (still not fully assembled and dyno tested) in my XJ which is why I am interested in this conversation. But after all the work and expense I have put in the Stroker and now looking at the trans....

I can see why a lot of people just opt for a LS1 with a 700R4 (or similar) transmission.
 
Well, electronically there are more sensors, more clutches, and one more solenoid. I don't recall exactly but the wiring harness in the Jeep had about 16 wires going to the trans...the Toyota has like 24 or something.

Shifter cable was my first thought, but not only is it on the other side, it rotates in the opposite direction.

They are so similar because they share the same housing...so dimensions are equal from one variant to the next...they are different with bellhousings/torque converter/output shaft/tail cone variations to suit all the different vehicles that Aisin Warner puts the core transmission into.

People, when given the choice, will usually take the easy and more traveled road cause it's...well....easier. Physical labor isn't the problem people struggle with in as much as it's the brain labor they want to avoid, from my experience.

Automatic transmissions are something most people have no CLUE how or why they work...they can just swap them in and out as one part and are good with that. I got tired of it being a big mystery "slush box" so I just took a class on rebuilding automatic transmissions and transaxles at my local community college, and rebuilt an AW4 on class time. These things are awesome and capable of being far superior to manual transmissions in ALMOST every way.

I am going through all of this to help Jeep owners take advantage of the more recent surge of boosted applications, but it will suit your stroker just fine. If this trans can push a 3100 lb Supra down the 1/4 mile in 8 seconds, it'll do the fine for your 3400 lb Jeep.
 
Back in the 50's... The Hydramatic transmission was a point of controversy witht he drag racing crowd adn attempts were made to either ban the transmission or only allow vehicle so equipped to race against other "automatic" trans vehicles. Come to think of it, NASCAR was not all that happy with them either.

It did not use a torque converter as it is commonly known but a fluid coupler. All of the torque multiplication was done by the 4 forward gears. Yup, a 4 speed auto ending in a 1:1 final and a 3.82:1 first gear. Released in 1939 for the 1940 model year Olds. Another wierdness was that it did not have a "Park" position. "Park was provide by... Putting it in reverse and shutting off the engine. A pawl would engage and there you go, park.

I have one of these boxes in my '52 Hudson Hornet. It was a thing of beauty. Problem was though, given the very low first gear, the axle had very high gearing which made breaking all of the speed limits very easy. Would hit an honest 120mph. Go ahead, ask how I know... I may still have the ticket around somewhere... Coast Highway 1, California, between Half Moon Bay and Santa Cruz.

Point is, a properly prepared auto will out perform a manual. And I for one, can't wait until child9 unleashes his monster...
 
I do appreciate this info on the AW4. I am curious about automatic transmissions too. I would like to rebuild one. I am going to see how my trans holds up to my 4.9. If it fails, then I will look into what failed and see if I can correct it. I think the rebuild kit from Import Performance would be a good place to start. As for the AW4 / A 340 E? I guess I would have to have two of them apart on the table and compare the internals.

I really thought the A 340 E and the AW 4 were more similar than they are.

I was wrong.

Keep up the good work and let us all know how you solve some of these problems.
 
Most of the "hard parts" are the same. They just have some different control mechanisms. Sprags will break from hard shifts that are too abrubt. You shouldn't have that problem with a stock valve body. IF you break it, my guess would be from clutch slippage, which results in heat and burning up clutch packs, which results in damaged thrust bearings and clutch baskets.

A properly modified valve body should IMO:

1. Increase clamping force of the clutches, thus increasing torque capacity of the transmission.

2. Increase the speed and firmness of shifts, but without being so fast that shifts are too harsh thus resulting in exploded sprags.

3. Increase general line pressure, This is part of the two line items above and supposedly will also result in more efficient power transmission to the wheels (less drivetrain power loss). This is one of the things that will be directly tested. (catch that, O-Guage?) :)

Rule number one with any auto is KEEP THE FLUID FROM BURNING UP. This has almost everything to do with the torque converter. I will experiment with a manual lock up button, and the a340e comes with a temperature sensor on the trans. It is external, so I don't see why this couldn't be used on an AW4.
From my conversations with the Jeepspeed guys, that has historically been the number one problem with the AW4 and is the primary reason why they don't use them in Jeepspeed events.

Check with me before you spend all that money at the import place. You can get all the soft parts for around $300 at a transmission parts supplier in your area. All the part numbers needed are listed in the rebuild thread.
 
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