How to make a a340 last(56kers take a nap)

[raven97990]

**EDIT** Just linking this thread to answer some quick questions. http://www.supraforums.com/forum/sho...=408088&page=2 Zazzn.

These are my own little tricks to make a a340 last. If you are rebuilding it, or having it rebuilt, install kevlar clutches, they tend to do best. Also, you must have a larger cooler on your car! Heat kills 90% of these transmissions. The other trick is to lock the detent(kick down cable) in full open, and to shim two of the accumulators, which is the only true way of decreasing shift time. this well affect the 1-2 and 2-3 shifts. Here's a brief walk through of that process...

Im in the process of making a full website with more intensive photos and walkthrough, stay tuned
After having one servere issue arise(we are working to correct it) I must strongly advise the following points.
1: It is best to do this mod with the transmission out of the car, the time saved by just pulling it will payoff on assembly
2: Get a new gasket, they are VERY sensitive to dust and such and can distort and bleed pressure
3: DO NOT OVER TOURQUE THE BOLTS. This is CRUICIAL you can warp the valve body or the transmission case when you do this. The spec is around INCH LBS, No airtools allowed for the valve body!
4: Do not mix your bolts up, they go in certain places.

The issue that has arrisen is a car shifting into reverse when it should go into overdrive, and it appears to be a pressure bleedoff issue, once we have that exact cause located, I will post it, and ways to avoid it.

Remove transmission(my preference)


Remove the transmission pan bolts, I marked most of them, you can figure it out...

Remove the filter with the three marked bolts. Also there are two metal tubes, I already had them out so I drew them in, gently pry back and forth and they will come out

The fun part, my recommendation is do not take the bolts out of the valve body, they are specific on their location.
Completely loosen the brown arrows, loose till there is slack on the bracket for the purple arrow, and remove electrical connectors marked by blue. Before you can remove the valve body, you must disconnect the kick down cable, see next picture to see the bottom side of it



This is what everything looks like once you get the valve body off, The two "things" marked are accumulators, those two are the only ones we are concerned with at this time

A close up of the accumulators

This is the first accumulator stretched out, the trick to getting them out is to push them all the way down and let them pop up... only way I can get them out.(this is the b-2 accumulator 1-2)

This is the bottom side of the accumulator(the one without the solid rod, that would be put in first going back in) This is where you want to place your shims, you want the shims to be about 1/3 of the spring travel, unless you don't care about you neck and you're tires breaking loose every shift.

Make 100% sure that you do not block this port, if you do, you're screwed.

This is the c-2 accumulator 2-3 see above for details

inside c-2 place shims as above

Again, don't block this port

This is just a reference picture, of how far the travel is, but you'll be figuring that out on you're own.
again reference, this is the outside of the tranny, to from the right, b-2,c-2, then the kick down cable.

Final reference, on reassembly, make sure this is how the shift lever looks, otherwise it won't work.. =)

Final note, the easiest way of locking the kick down full open is to cut the cable(with valve body and transmission fully together) and then lock it with a cable lock or other vising device, unless you want to build a wedge to put in when the valve body is out, all a matter of preference.

Not too descriptive, but I hope this at least will give you all an idea of where to start with when upgrading a a340. Also, I don't see much need of a upgraded valve body, from what Ive researched, they are rarely more then what you can do you're self here, or slightly enlarged passages, not worth the money to me.

[mdr40z]

have you done this on more than one car, I mean is there a good track record? I recently had mine rebuilt with all the good stuff and I'd like it to survive as long as possible

[raven97990]

I've done it to two of my transmission. When you have a performance build, this is generaly a step that they take, shimming the accumulators. A general rule, anything you feel, the transmission doesnt. Now, locking the kick down isnt nessacary, another step is to just adjust it tight, so it kicks the pressure up sooner, that will help make a more civil ride.

As far as where these "tips" come from, I am ASE certified in automatic transmissions(as all other areas) and I sat down for four hours with one of South east Toyota's best transmission guys while I was down for training, and this is what we devised as the best "simple" things to do to keep the transmission from dieing.

[Zi4life978]

Awesome write up and interesting pictures Raven.

[PSI-GUY]

i just want a a decently priced built auto that will handle 550 hp with ease and not, be a hard install.

[SlimFastSupra]

Good stuff. There have always been long write ups without pictures and it's impossible to imagine what is said.

The pictures are great.

[Ckanderson]

Awesome right up... I nominate this a FAQ sticky...

BTW... can you take photo's of the shims?

[fstlane88]

Wow very informative, how different would the procedure be on the 1JZ's A342E?

I'm quite tempted to try this since my transmission is just sitting on my garage floor right now.

[mdr40z]

if the tranny is in the car, can you do this without all the parts and pieces falling out? I just just see me trying to do this and losing some little ball or piece

[raven97990]

I strongly recomend pulling the transmission, as there are alot of things that have spring tension, as in the accumulators.

As far as shims, I havent performed the mod on this transmission yet, but I will be, in the past it's just been washers. This time Im planning on taking solid stock so it's a single piece, I will post that picture when I do it this time around(should be withing a few weeks)

[raven97990]

Originally posted by fstlane88
Wow very informative, how different would the procedure be on the 1JZ's A342E?

I'm quite tempted to try this since my transmission is just sitting on my garage floor right now.

Should be the exact shame, we've done this to a new A340 on a supercharged Tundra, so it should work just the same.....

[flubyux2]

very cool, i was anxiously awaiting pics. this is cake compared to the rest of the stuff ive done.

what did you use to shim the accumulator springs... washers? split washers?

bar stock would be pretty good... but, how do you put the shims down in the accumulator body yet avoid having them seated in a way that blocks the fluid passage?

when rebuilding the tranny, is there any benefit to adding more clutches to the pack or little tricks to help out there?

[stroked_7m]

dude you have no idea how much this helps. thank you. where did you get the kevlar clutch packs? please take a picture of the shims you used. if the clutch packs are affordable i may rebuild one of my trannys with them

[stroker]

very nice write up. Thank you.

[ZaZZn]

hrmm wondering where i should stick this.

[raven97990]

Sorry about the lack of clarity in the shim placement, hopefully these two pictures help. Also, for the first transmission we used standard flat washers, but for the transmission Im prepping now, Im going to use barstock and have it machined. Also for kevlar clutch's, I've not yet built a transmission with them, we've used Toyota parts, the Tundra has 350hp to the rear wheels(it is supercharged) and he beats the hell out of the truck, and the transmission is still going strong. After I swap the transmission out of my car, that one is going to get full kevlar clutch's, and will be built considerably.


Again, this is b-2, but with the area's labled. When I refer to "top" It is the part that is visible when you are looking down at it(the one with the metal rod inside the spring)

The shim goes inside the accumulator, the purple mark is the "shim". This doesn't matter if it is solid or open, just as long as it makes full contact with the spring.

By only shimming these two accumulators, we keep the 3-O/d shift soft and resonable, and it also keeps the shift into reverse reasonable, we are only affect the gear shifts that will take the most abuse.

As far as adding more clutch's, I don't see it as nessacary, the a340 is a very good transmission,toyota used it almost completly unchange from at least 1986-2004, In 93 they removed the kickdown cable and went to a electronic control, and added some extra sensors. The 2jzgTe version gets on extra clutch on c0 I think it was, which is the only internal change. The sc430 and ls430 used this transmission, some other's used it I can't remember...

As far as where to "sticky" the thread, I was thinking possibly under Technical, as it more applys there now, and when I get unlazy, I'll clean up the pictures with fancy arrows rather then my poorly drawn ones.

[DeanMarcum]

That is pretty much what I did. However, I also shimmed the Co accumulator which does not seem to have any ill effects (I have the throttle valve cable adjusted to stock spec). I did not shim the Bo accumulator as that is only used for the overdrive circuit. Do you see any problems with having the Co shimmed?
I did this install with the trans in the car. It is not too terribly difficult as the accumulators have dual o-rings so they still hold with the shims in place. The check ball body was a pain but a bit of "dissolvable grease" held it in place during re-assembly.

Thanks for the very cool and useful writeup, I never take pictures

[SlimFastSupra]

This should be posted on a website, and this topic should be locked for reference or the thread will eventually turn sour.

[raven97990]

Originally posted by DeanMarcum
That is pretty much what I did. However, I also shimmed the Co accumulator which does not seem to have any ill effects (I have the throttle valve cable adjusted to stock spec). I did not shim the Bo accumulator as that is only used for the overdrive circuit. Do you see any problems with having the Co shimmed?
I did this install with the trans in the car. It is not too terribly difficult as the accumulators have dual o-rings so they still hold with the shims in place. The check ball body was a pain but a bit of "dissolvable grease" held it in place during re-assembly.

Thanks for the very cool and useful writeup, I never take pictures

I don't see anything that could go wrong by having the Co accumulator shimmed, I just addressed the accumulators where most people would be driving hard. In theory, not having an accumulator is the best thing you could do for the transmission, but it'd hurt you're neck. And the check ball was the one that I figured would be the biggest pain in the butt, I've just always had the transmission out when I did the work.

[MKIII87Turbo]

Haven't seen this as a sticky yet.

Well I did this today on a tranny that is out of my car. I used (4) 5/16" aluminum washers on each of the 2 accumulators. It came out to about 1/4 in thickness. They were a little bit to large in diameter so I stacked them between a bolt and nut, put that into a drill and spun them on sandpaper to get them smaller. I also made a bracket that holds the cam for the kickdown cable open. All of this took about an hour to do. Since you are in there you should replace your filter. If I have the will to do it, I'll be putting this tranny in tomorrow. I'll report on this and see how it works out.

I know on this tranny (91) it does not have the solid rod, and the springs in the top are held in with snap rings. The B-2 accumulator has 1 spring on the bottom, and the C-2 has 2 springs on the bottom. (I forgot where they went and had to look at the TRSM) The shims do go into the same place though.

This is a temporary tranny for me and the original one I take out will get a full rebuild with Kevelar or Rabestos Blue frictions.

[ZaZZn]

gonna put it in the Tech section. and stick it.

[raven97990]

Originally Posted by MKIII87Turbo

Haven't seen this as a sticky yet.

Well I did this today on a tranny that is out of my car. I used (4) 5/16" aluminum washers on each of the 2 accumulators. It came out to about 1/4 in thickness. They were a little bit to large in diameter so I stacked them between a bolt and nut, put that into a drill and spun them on sandpaper to get them smaller. I also made a bracket that holds the cam for the kickdown cable open. All of this took about an hour to do. Since you are in there you should replace your filter. If I have the will to do it, I'll be putting this tranny in tomorrow. I'll report on this and see how it works out.

I know on this tranny (91) it does not have the solid rod, and the springs in the top are held in with snap rings. The B-2 accumulator has 1 spring on the bottom, and the C-2 has 2 springs on the bottom. (I forgot where they went and had to look at the TRSM) The shims do go into the same place though.

This is a temporary tranny for me and the original one I take out will get a full rebuild with Kevelar or Rabestos Blue frictions.

Good luck on pushing it to the limits! I really plan to put it to the test, 170K transmission, these mods, with a good cooler, and 500HP to beat on it, but be smart with it, and just see how well it does, the most likely failure at gross power is going to be a planatary gear breaking..

[Mike 92LX]

Synthetics? Or half and half mix?

I am starting on cammed 1J twin BPU/nitrous car and I will be using an auto so this is very valuable to me. Thanks!

[raven97990]

Originally Posted by Mike 92LX

Synthetics? Or half and half mix?

I am starting on cammed 1J twin BPU/nitrous car and I will be using an auto so this is very valuable to me. Thanks!

Ive always run Dexron with a bottle of lucas.... no problems yet

[nosechunks]

This is sweet information!!! i was thinkin about how to go about making the automatic stronger and i guess this is the way to do it. about how much power do u think this would handel?

U said that unles u dont care for ur neck or ur tires spinning on everyshift dont shim it more, does this mean that if u shim it for like 2/3 instead of 1/3 itll literally break yo neck? lol

Also that port that u cant block, thats isnt where the shim goes, its where the accumulator jammy sits right?

EDIT: i just read up more on this and from what i read, the first to second gear Sprag is the weak link and it will actually strip or break. i dont really know all that much about auto tranies, or about what this Sprag thing is but i was just wondering if doing the things stated in this thread will help that or not.