AW4 rebuild/upgrade build thread

[child9]

I've got a couple threads going now but thought this should be on it's own. I'm tearing down and rebuilding an AW4 with all new soft parts and valve body modifications. I have the Supra mods known and available to me but I want to tailor the mods to the Jeep platform. Increasing the overall torque capacity, strength, shift firmness, and shift speed are the primary goals. The AW4 is already a great transmission, and I am striving to make it better. I kinda want to gear the AW4 to handle the turbo applications that are starting to show up... like Bryson's turbo manifold and my 2J swap. Turbo setups historically seem to have been largely avoided due to the conception that they will lack low-end torque. I believe this to be a misconception and have set out to prove it. Either way, dyno charts will tell, but regardless of the powerplant, I think all of us as Jeep owners would like to have an upgraded and affordable AW4 auto option for our Jeeps, whatever you intended use for the vehicle.

Every Saturday between 1 and 6 CST I will be working on this first transmission rebuild. There was NOTHING wrong with this trans, but I am taking the opportunity to take it apart and learn it so we may all benefit. Here we go.

Day 1 was mostly prep and removing bellhousing, fluid lines, sensors, rear housing, etc.

Day 2:

Started tearing down the trans today. Once I got the valve body off I was FREAKED to discover that a piston was actually missing from my AW4. What's even stranger, is that the trans always felt fine. I am sure that it was shifting into overdrive, but the XXXXing OD apply piston was MISSING. I'm holding one of the other pistons up next to the springs in the HOLE where a similar piston should have been. Really weird. It's obvious that this trans has been taken apart before. I will buy a new replacement piston and install it PROPERLY. Sheesh.

 

[trippled]

what type of modifications are you doing to the valve body and such? im interested to see how the tranny reacts to them

 

[Seiler]

Subscribed. Looking forward to updates. :thumbup:

Scott

 

[child9]

Raising main line pressure, shift speed, and shift firmness.

 

[GoBrandonGo]

im in. keep up the good work.

 

[child9]

Came across this in the archives. Re-posting.

http://www.naxja.org/forum/showthread.php?t=23644

 

[xcm]

thanks for pooling resources and posting this thread. any chance for pics of your custom snap ring pliers and any other cool stuff you come across? ive got one apart right now to feel if i can rebuild the blown trans in my dd... so far got it apart to the valve body.

 

[GrimmJeeper]

This post from 2008 may be of some interest to those reading this thread.

http://www.naxja.org/forum/showpost.php?p=244171934&postcount=14


Also, that overdrive plunger is there, that one is installed with the spring facing outwards instead of the other way around like the others.

 

[child9]

Yep, there it is right there in the book. That's just silly of me. Ah, well, this is how I learn. At least this time it didn't cost me money or hurt.
Still wish I could edit it though, ha...what a drama queen I was being... lol.

 

[child9]

http://www.makcotransmissionparts.com/mm5/graphics/Catalog-pdf/A340.pdf

Really close. Also really nice exploded view.

 

[GrimmJeeper]

We all make mistakes, no harm no foul

 

[NorCalChris]

Check out my thread here. It might help you out a bit. Not sure if you plan on shimming the accumilators or not, but it helps alot. Just dont over shim or else :explosion.

 

[child9]

I didn't get the new clutch packs yet, and I need to get a new band and internal cir-clip for the band piston, so I didn't work on the AW4 this weekend.

 

[child9]

I acquired the appropriate clutch packs, the 3 tt supra sprags, and the overhaul kit I need for the AW4 today. Wooo hooo.

The friction pack is the same as this one except for the smaller grey disks. The thicknesses in the forward clutch are different by several thousandths of an inch per disk. I actually ended up getting all of them separate for the AW4, since that's the only way they had them. This way I can just buy a "kit" I'll assemble. The "A340e" for the tt supra actually has this friction pack pictured. Unfortunately there are no bands to be had that I can find. Infinite back order because they all come from Japan. I'll make sure the one I currently have is within tolerance, and well, it'll just have to do.

Also it should be noted that there is NO reason to spend $300+ dollars on the raybestos "blue" friction disks that others will try to sell you. The normal raybestos yellows are more than adequate to hold over 700+ HP to the wheels in the tt Supras. Sprags are the part that goes, if anything. I'm using the sprags for the TT Supras. I don't know if they are any different (read stronger) than the AW4 sprags, but I'm going to use them anyway.

This information comes from a person that apparently is highly regarded and I dare say a "legend" in the automatic transmission world here. This is the same person that will be figuring out (with me ) the appropriate valve body modifications to be made to the AW4 valve body in the near future. We have a lot of "worm hole" tracing to do ahead of us, lol...unfortunately we are unable to schedule enough time to sit down and do it at the moment. Maybe later in May. Either way, that will be the last thing anyway.

 

[XJEEPER]

I'm sure you see the value of documenting the part numbers and sources of your build for all who are following along. Thanks for the info provided thus far.

 

[child9]

Part numbers? Was I supposed to write those down? LOL. Of course.

 

[child9]

I located 2 bands just a minute ago, so I bought both. Saweeeeet!

 

[child9]

Clutch pack components from Jerry's Transmission Parts in Austin, TX
Quantity Part Number Description
6 ......... 97107 ....... A340 Forward Friction
4 ......... 97101 ........A340 OD Brkae Friction
4 ..........97103 ....... A340 Direct Friction
5 ......... 97103A ..... A340 2nd Friction
7 ..........97104 ........A340 Low/Reverse Friction
2 ..........97108 ........A340 OD Direct Friction

1 ..........97500F ......Pan Gasket-Dura

1 ..........89728 ........A140/A340 Overdrive Direct Sprag
1 ..........97821A ......A340 Intermediate Sprag
1 ..........97724 ........A340 Low Sprag

1 ..........2195 ..........Overhaul Kit

94995 AW4 A340 AW30-40LE Transmission brake band from www.transmissionpartsusa.com

 

[child9]

Started replacing everything today. Everything in this tranny looks really good, I'm pleased to say. This is for all intents and purposes turning out to be a "soft overhaul".

Every friction disk I removed from the stock AW4 was really dark grey. I replaced them with raybestos yellows. I looked for blues, but after talking to several people, including the guy who builds all the BL autos, they are not needed and a waste of money. Every BL trans uses yellows. I'm gonna take that "other" list of upgrades and get some input on how much else of it is BS. Anyway so far the stock frictions were also showing barely any signs of wear. I've done the forward and overdrive clutch packs and one of the sprags so far.

I have every confidence so far that this setup is going to be what people have been looking for as far as upgrades for the AW4. The valve body mods will be the key. That will dictate the balance between performance and longevity.

 

[child9]

Here's the damn plunger I was freaking out about. Still a little embarrassed, but I'll get over it soon enough...

So Casual put a link up to my.is, and this is what I found. I joined and spoke to one of the users, and I may be getting the sprag I have circled here. It is obviously much stronger than the one I have. The question I am trying to figure out is where it can go, if it can. Specifically I want to beef up the 2nd gear sprag, and I don't know if this is it. I have read about people switching parts from the a650e to the a340e, but have no specifics yet.