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

[raven97990]

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.

[nosechunks]

lol yea i kno i was just kidding about when it would actually hurt u, im currently building my motor up and swapin from auto to w58 because it was cheap and my autos getting kinda wornout. im gona build up the auto over the winter and swap it back in for next summer and im really likin these things im finding out on how to make it stronger. so far the only thing im worried aobut with this tranny is the sprag gear thingy.

one more question, if i were to leave the throttle position cable hooked up as it was stock just maybe tightened a little bit would it still shift really fast just with a little less kick? or since the line pressure would be less would it shift slower as well. likei said im not all that knowlegeable about automatic trannies.

[raven97990]

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.

[nosechunks]

Well, if making it shift fast is just a matter of shimming the accumulators, then how would you make it shift harder? or is that all in the line pressure in the tranny?

MKIII87Turbo, any updates on how this trannys working?

[raven97990]

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..

[mdr40z]

It is so embarassing I contemplated not coming forth, but having this unique ability to laugh at my own idiocy sometimes and to help others with this mod, I have to tell on myself....

When I took it back apart and after I had verified that there were no cracks or warpage of the trans, I slowly and carefully put it back together and found, with help from these pages from the TSRM, the spring problem.
With my handy-dandy dial vernier caliper I found that I had somehow gotten the springs mixed up (a hazard of doing the job with the tranny in the car I guess) maybe a C-2 or B-2 in the C-0 position. I don't know if it was finding reverse or first, I'm not sure which one, when shifting to OD at about 50-60 mph. All I know is it left two nice black skid marks on the pavement before I had time to push the button again. Of course when I saw that spring was about 200 thousanths too short I knew immediately.
This time I went back together with about 5/8" shim which is violent to say the least but not at all uncomfortable except at slow speeds. I also think that I would benefit from a single driveshaft, it seems to be rough on the carrier.
I know that I initially did some damage to this tranny after the rebuild and I'm not happy with the place that rebuilt it. I know I roasted it at least once, I was running 1.1 bar or so, and I can smell the burtness in the trans, I've since turned it down. Had I known of this mod that may not have happened although I do think it's too much for the 340 to handle. We'll see how long it lasts with this mod, so far it is a huge differance. If it doesn't survive I will do the build myself once before giving up and going GM.
Many thanks to Jared and company for this mod I think my last tranny may have survived had I known this. I do think just about anybody (except for me it appears ) could do this mod with the tranny in the car with the help of that green dissolving grease or two people holding the pieces in the right spot, although certainly the right answer is to take the tranny out. Good luck folks and here are the TSRM pages.

http://www.cygnusx1.net/supra/librar...at/AT_136.html

http://www.cygnusx1.net/supra/librar...at/AT_137.html

If I think of anything else I'll edit and I'll keep you updated.

Mark

[nosechunks]

so when u were running 1.1 bar it was slipping? what did they rebuild it with? with 5/8ths of a shim does it cherp second and third? and what did you do with the cable? did u lock it wide open or are u just running it stock spec?

lol sry for the questions, just trying to find out as much as i can about this, the more and more i hear the more and more i want to put my auto back in.

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???

[raven97990]

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...

[MKIII87Turbo]

I still haven't gotten the tranny in yet. Will probably try this weekend. After 3 hours trying to get the top bolts out, I gave up. Going to take the tranny crossmember off and drop the rear down and see if I can get to the top bolts better.

[mdr40z]

[QUOTE=nosechunks]so when u were running 1.1 bar it was slipping? what did they rebuild it with? with 5/8ths of a shim does it cherp second and third? and what did you do with the cable? did u lock it wide open or are u just running it stock spec?[QUOTE]


Yes, it definately was slipping (note that this was BEFORE this mod), it was rebuilt w/blue rabestos (so they said, I have my doubts), with an extra 1-2 clutch. I burnt it so bad on a 1-2 shift I could smell clutch pack. It sure seems ok now tho, I need to flush it again.

Yes, chirp is a polite way to put it. It bangs REALLY hard, so hard I'm a little worried about the rest of the drivetrain. Also, I think that 5/8" is about all you can go, it gets hard to put back together and is probably the equivalent of no accumulator at all.

Yes, cable is locked wide open. IMO you must lock it all the way open, I think the only reason Toyota didn't is that you can actually hear the fluid flowing at idle. It's the only thing that keeps your pressure really high at low rpm.

[mdr40z]

I still haven't gotten the tranny in yet. Will probably try this weekend. After 3 hours trying to get the top bolts out, I gave up. Going to take the tranny crossmember off and drop the rear down and see if I can get to the top bolts better.

You need to drop the rear of the tranny down quite a bit, then put about 4 feet of extensions together, piece of cake then.

[williamb82]

ok, so these acumulator mods, kevlar clutchs, and a kevlar band, 4 runner trans pan and big trans cooler should do it right? id rather have o/d then go th400 like i was planning. great writeup btw.

also, im always hearing about adding clutches. how hard is it to do this? what are the benifits other then what ive heard about firmer shifts and any cons? sorry if it sounds stupid, i am a noob when it comes to auto's.
william

[nosechunks]

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...

Yea i was just wondering for like around town just shifting it manual every once and a while

Well the b&M shifters can be used on 700r4's and ive seen them on trannys with just shift kits so i guess you dont haveto have a manual valve body, only reason i ask is becasue i absolutly have the stock shifter. its all wobbly and retarted looking and uncomfortable.

MRD40Z: wereu running a tranny coller at that time when it was slipping?

[mdr40z]

MRD40Z: wereu running a tranny coller at that time when it was slipping?

Yes, I have a large cooler, Oh, and an IPT valve body

[AllanL]

any luck with the reverse issue yet? id love todo this but im afraid it would be a step backwards *boom tish* :P

[raven97990]

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)

[AllanL]

ok good so it was only this one person having the issue due to incorrect spring placement.



ill attack this asap

[chris davey]

Well, I am afraid to say that some of that went over my head.

Is this the process that an auto place would go through when you ask for a shift kit?

So you fitted a shim which is a small circular object between the accumulator and the spring. This was 5/8" thick and this is the absolute thickest you would use. If so, I think maybe a 1/2" one would do the trick for me.

Locking the kickdown cable open: by this you mean making the bracket that the kick down cable is attached to stay in the open position instead of returning to the usual place because of the spring. If you were to do this, would you still need the kickdown cable attached? Is this the part of the mod that increases line pressure or not?

So this mod is not strengthening the auto as such, but slightly modding it to shift quicker so that there is less time spent boiling the fluid.

BTW I already have 2 gearbox oil coolers.

thanks, and sorry for the stupid questions.

[MKIII87Turbo]

Well I'm alot closer for testing this mod out. I got the old tranny out and the modded (sp) one in today. I just have to hook all the periphials back up tomorrow morning.

[MKIII87Turbo]

Had to use a jumper wire to start the car, but, with the 1/4" of shims is shifts nicely. A little firmer than stock but nothing radical. I will opt to go to about 7/16" or 1/2"next time though for a little firmer shift. (Going to rebuild original auto) You can hear the fluid flowing with the kick down cable locked in full open. Again nothing to radical. For the 40 mile drive I just did, I was upshifting and down shifting and everything worked fine first through fourth. I would recommend having the tranny out to do this mod. Other than wanting a more firmer shift this mod is great.

[chris davey]

Is there any downside to locking the kickdown cable open? Does the kickdown cable work like a thermostat? ie. when it opens the fluid is sent through and then through the cooling system and back to the gearbox?

Also, I have been told that shift kits usually upgrade the valve body but don't shim the accumulators. Is this a one or the other sort of thing, or could you do both?

I will be trying this with my spare auto this weekend hopefully

[MKIII87Turbo]

See Ravens post #30. The kickdown cable does not deal with temperature, only line pressure. Besides the noise of the fluid and firmer shifts across the gears, I see no other downside.

As for shift kits, IIRC (If I remember correctly) they do not make a shift kit for our trannys. This mod does basically the same thing. Now if your talking valve body modifications thats another book.

If you have the tranny out its pretty easy. Just make sure to replace the filter, TORQUE the vlave body back on, and remember where the springs for the accumulators go.

[chris davey]

Yeah, the auto place I know of does shift kits but they are valve body mods. So this mod is a TRUE shift kit then.

I will practice on my spare auto that is out of the car, and then have a go on the one I am using.
thanks mate.

[MKIII87Turbo]

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.

[raven97990]

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...