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· Captain Hammer
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**EDIT** Just linking this thread to answer some quick questions. http://www.supraforums.com/forum/showthread.php?t=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.
 
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· Captain Hammer
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Discussion Starter · #3 ·
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.
 
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· Captain Hammer
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Discussion Starter · #10 ·
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)
 

· Captain Hammer
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Discussion Starter · #11 ·
fstlane88 said:
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.....
 

· Captain Hammer
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Discussion Starter · #16 · (Edited)
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.
 

· Captain Hammer
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Discussion Starter · #19 ·
DeanMarcum said:
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.
 

· Captain Hammer
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Discussion Starter · #22 ·
MKIII87Turbo said:
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..
 

· Captain Hammer
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Discussion Starter · #24 ·
Mike 92LX said:
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
 

· Captain Hammer
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Discussion Starter · #26 ·
nosechunks said:
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.
Well, I cant give you aproximant amounts of shim that'll start to hurt you physicaly. But there is a point that it will hurt you. Thats why I suggest 1/3, it works great without putting too much kick into your shifts.

In regaurds to the sprags breaking, that is the weakest link next to the overheating, smooth shifting characteristics of the A340E. Im doing some material research, and investigating the costs of building new gear sets out of a high strength alloy. Im really going to be testing out the basic mods once I get my car back on the road, the transmission has 175K on it, will have these mods done, and the motor is going to make 500+hp... I will find what breaks.

The biggest thing you need to remember is to drive smart, A wise choice is to get a remote controler for your boost controler, and at the drag strip launch at lets say, 12 psi, then just past the 60, once you are hooked up and moving, hit it up to 24 psi...(depending on your setup) That will help your transmission last longer as well.
 

· Captain Hammer
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Discussion Starter · #28 ·
Not applying full presure by binding or locking the kick down in the full position won't really adversely or positively affect anything, a slightly tighter then stock setting would work well. Dean Marcum says earlier that he has his set to stock spec, and makes just over 400hp. That is a choice/preffernce item.
 

· Captain Hammer
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Discussion Starter · #30 ·
Shimming the accumulators makes shift time shorter, locking the detent open increases line pressure, which makes the "harder" shift. You will feel more from the shimmed accumulators, but they work best togather.

And for the problem transmission, that would shift into Reverse when going into O/D was caused by a C-0 accumulator spring installed in the wrong side. We'll get more information on it later, when I have some more time to get pictures and such..
 

· Captain Hammer
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Discussion Starter · #33 ·
nosechunks said:
on another note, would a shifter like the B&M star ratchet shifter work on these trannies? it says work on most 3 and 4 speed trannies. so i figure it would shift from first to third and then have a switch for overdrive right?

Oh yea one more thing for raven, is it possible to get rid of the gear to gear pause when manually shifting from L to 2 to D with out having to buy the paddle shifter thing???
1. If I remember, isn't the B&M for manual throttle bodies? I don't think it'll work on the a340...

2. The transmission is electronicly controled, so the only way to get exactly what you want is to use the electronic shift control(paddle thing) BUT doing this mod causes you to have quicker shifts between those gears, it shortens the time, so it'll acheive what you want. Are you looking to drag race your car? Beacuse in most cases, letting the computer do it's own thing is alot better. I use to shift the gears myself going down the track, and then decided to leave it in a drive and see what happened, I picked up 2/10ths doing it that way...
 

· Captain Hammer
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Discussion Starter · #41 ·
AllanL said:
any luck with the reverse issue yet? id love todo this but im afraid it would be a step backwards *boom tish* :p

Yes, look at post number 31. We are working on a revised walkthrough, that is clearer, and all in one post(too many pictures right now)
 

· Captain Hammer
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Discussion Starter · #50 ·
MKIII87Turbo said:
Another update. When you are at stop signs you have to push on the breke pedal just a little bit harder due to the full line pressure.

For some reason, that just cracks me up,

We are currently investigating some more posibilties of actualy valve body modifications(boring out) to increase flow and decrease noise, also still working on a full set of custom gears for the pig... I am determined to make a cost effective A340e that will hang with the th400 boys...
 

· Captain Hammer
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Discussion Starter · #52 ·
MKIII87Turbo said:
Toyota has been using them for years and IIRC so do some Jeeps (AX4).

Eh? Using what?
 

· Captain Hammer
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Discussion Starter · #54 ·
So you are saying the a340 has been used for years? Yes, in Lexus and Toyota, was used untill 2004 in the tundras.....
 

· Captain Hammer
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Discussion Starter · #56 ·

· Captain Hammer
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Discussion Starter · #59 ·
88tjason said:
hello, any help? :dunno:
Sorry about that....

mdr40z I believe was having that issue as well, is it all the time, or only at wot? Can you lift slightly and it shift? I've never had this issue, so I'll have to go based on theory with some more information.
 

· Captain Hammer
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Discussion Starter · #62 ·
AllanL said:
i dont see a reason to tie the line pressure cable in the WOT position, as when you want it to shift hard you will be at WOT anyway!
I strongly suggest tightening it. Yes, you don't have to, but more pressure is generaly a good thing.


88tjason said:
yah, its only at WOT, and lifting slightly does cause it to shift. Its fine any other time. Could it be air somewhere? or I not put something back correctly?

Thanks for any help. Love the auto, just hate when its not working correctly. It shifts faster than a stick when racing. :bigthumb:
Well, I will tell you what, you and the other guy Mark who is having the problem shimmed more then I did. I don't know why or what is causing it, Im still hunting for any kind of a guess, but it seems when you lift ever so slightly, it will shift. Let me suggest this, if you can, try unlocking your cable going into the transmission, and adjusting it very tight, but still connected to the throttle linkage... to see if it is a pressure issue.
 

· Captain Hammer
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Discussion Starter · #64 ·
88tjason said:
nope, sorry. That didn't work. With the ect switch to normal, it goes to 6500 rpm with no shift. with switch on it does tha same thing. I guess its gonna have to come back apart. might as well go ahead and rebuild it. Thx.
Only thing I can think of is the increased amount of shim is affect pressure somewhere else... I still havent pinpointed what else would be affect, so if anyone has any ideas, chim in...
 
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