Hello agai n yotatech. Im gonna be posting here about repairs and mods to my auto transmission while I'm working on my 1st gen runner engine rebuild.

For starters, no I will not be manual swapping, at least not right now. I can afford ATF a filter and the transgo kit and barely anything else considering rebuilding the 3.0 is already underway which is controversial enough. Again don't make this a debate about why I should. I cant afford that. What I can say is I have time and energy to work on the auto, and after the first weekend of work to it; I am somewhat less intimidated by what I saw.

As far as function of my trans went before, it worked pretty well but not perfect. One of the only things I can really note is that it had an incredibly rough 2-3 shift. Otherwise worked like any other trans behind a 3.0. Not it's fault the motor is a little slow. After dropping the pan (sway bar and front driveshaft from t-case must be dropped) I find a suspiciously clean oil pan. Usual crud on the magnets but thats what a magnet does, attract the fine stuff. Nothing to note in the filter either. Fluid was for the most part bright cherry red not cloudy not smoky smelling so this is a better start than I originally hoped for.




We also find an aftermarket shift solenoid that I believe is also for the 2-3 shift. This was maybe what the P.O. thought would fix the trans issue but Ill show exactly what I think was causing rough 2-3 shift later. Note the blue solenoid on the left, this was installed towards front of trans, so in the 1-2 shift spot. Seen them on ebay and other parts sites for cheap. I previously thought I'd be replacing this but it feels tight and functioned to some degree if I did have shifts at all. Will be testing before I put any of them back in.



Next was the tubes...
I didn't see them in any videos or photographed posts about a340h teardowns but uhhh mine had tubes inside. At the right of the image towards the back of the trans. I don't know where they go to or what they do but they're there though. They were incredibly snug friction fit, pretty hard to pull straight out. Thought I was gonna break something.



After this, removing the valve body is mostly straightforward. Unscrew all the bolts, left a couple in because I am working upside down and don't want to drop it into my dirty workspace. Have a receptacle like a clean plastic lined box or something you can drop the VB in and get out of the way. This is also where you don't want to get too hasty and drop the several things that are about to bounce out of your transmission. Theres a black plastic with a little tiny spring and captive ball bearing item that will most likely fly out and into the dirt like it did for me. It's usually referred to as a one way lube valve. Allows oil to stay in the torque converter while not running so it doesn't drain everything into the pan overnight and have to fill up again next startup.

Found a mysterious long spring in the front drivers side corner of the VB. It has a landing spot like the accumulators do. I don't actually remember what this one goes to. Oops.

This trans also has three accumulators which build fluid pressure to shift up into the next gear. Springs on both sides in this version of the A340. The springs are not the same, they all fit differently and most likely have different values in terms of pressure/ strength. They are capable of dropping straight down but likely won't since their job involves being airtight. If you have shop air, there are holes very close to each one that you can blast air into to shoot them out through the oil passage. Pushing them up into the trans and then letting them launch themselves back out is also possible.

This is where I found my smoking gun, spring in the 2-3 shift accumulator is very very broken. Good amount of ground glittery metal at the bottom of the spring cup inside the large end.



After this, pan is back on and goodnight to yota...

for now

If people want a much more documented and photographed writeup of cleanup and installing a Trans-Go kit on this valve body, feel free to sound off below. I am also open to filming it on my gopro and posting to YT if there is demand for accurate documented video of the process. Thanks to Timmy the Toolman and James Tyrell's videos on YT on the install of the kit and including pulling parts and valve bodies. Big thanks to CartuneNZ, has a great video on helpful tips and breakdown of the individual components and functions of these transmissions.

Hardest part of this rebuild looks like it will be sourcing parts. I have found one single shop in Eastern Europe with the C-2 accumulator including springs listed in stock on their site. It is very possible that any other transmission shop in the US has it too. Have not called around yet. If anyone knows people or places that have transmission parts (filters, input shaft seal, oil pump o ring seal, valve body gaskets) I would greatly appreciate being informed.

If YOU have an A340H sitting around and don't mind lending a spring let me know. Thank you.

Don't give up on your auto transmissions, more to come.

 

You might post a link to the jtube vid. Would be interesting.

Also, post up what year you have, and maybe what state you live in.

 

great point. It’s a 1989 v6. Northern California

 

These Aisin transmissions are the same units found in jeeps, they go by the name AW4. That may help you with locating parts.

 

spring might still be available. i grabbed a random V6 model number to look this up. Best to get yours and recheck

 

Nice find, what site is that? No kidding I did hours of searching and couldn’t find a thing. Ended up buying someone’s used out of a Supra trans off eBay. I’d feel better if I had a brand new one though as well as o rings which it looks like it has.

I will need to make sure it’s same valve body though, they changed a couple times pretty soon after being used in first gens from what I found.

I will also probably be posting update and all the relevant helpful pages I found later today. Lots of info out there on these trans just not all on this forum lol.

 

A340H update:

Disassembled the valve body on the bench. Must have missed a tab on partsouq the first time around but I eventually found the part numbers for internal components for these transmissions there. The parts seem to be scarce but ToyotaPartsDeal does have most/all of them for sale at the best prices.

The Trans-go kit calls this style of valve body a Type 1. It seems like these are the earliest versions for the A340. None of this information applies outside of this style of valve body.

I took time to highlight important parts/areas on the valve body halves since I dropped pieces multiple times and never really saw a full map anywhere else.


Lower half of the valve body is above:
The items in orange are flat topped pressure relief and check valves, small springs underneath them, good place for gunk to accumulate.
The green is another basket shaped check valve with a ball bearing sitting in the middle. No spring underneath.
The filters in red are small sized strainers. Part# 3544130020 for the lower half. They're all plastic basket and fine wire mesh. Very easy to mangle seemingly because someone smashed both of mine before I ever opened this trans.
The filter in blue is a taller strainer. Same plastic basket and wire mesh construction.




Upper half of this valve body has all of our check balls. This one came with 9 and the kit called for removing 2 of them.

The yellow spots are where the trans-go kit wanted the balls removed. Not sure what circuit they are for.
The red are the small sized check balls, these are .218"
Blue is the large sized check ball, this one is .250"
Green is highlighting a vertically installed round pin.
Light blue is a retaining clip that goes over one of the internal valves.
Pink is where a filter strainer should be. Mine was missing. Part# 3544130031

After the valve body work is done the kit wants you to drill out a few holes in the separator plate between valve body halves. I went with the "truck" shifts mod and not the "hot rod" setting. Probably too aggressive for the 3.slow anyways.

I originally ordered someones set of used supra transmission springs but I'm going to go ahead and order a new spring from Toyota Parts Deal since they have the one I need in stock. I trust a new spring more than I trust the used one.


From left to right we have accumulators B-0, C-2, B-2, and the springs for accumulator C-0 which I left installed in the transmission.

The small plastic piece retaining a ball bearing is a backflow check valve that stops oil from flowing out of either the torque converter or cooler lines. Can't really tell which yet.

Partsouq has item numbers for all of these parts again including o rings. I will be putting brand new ones on all of these accumulators. Yes these ones did a fine job sealing but they are under pressure and realistically speaking, a wear item. The trans-go kit also provides more/stiffer springs and spacers to install on these meaning they will be building more pressure than they ever did before.

If you buy these from a shop that sells online they will only sell kits including the wear items inside the transmission. It looks like I will be buying all of these filters, o rings, and spring for mine for around $60. This is probably the most cost-effective way to go about refreshing these autos.

On top of that I am dropping in new solenoids. I went with the atp kit from Rockauto. Runs about $150. Saw more than one good review for them and since mine were failing, the best practice is to replace them all. Good insurance.

I will keep updating when I have more progress. Slow going since I have to travel to actually work on this rig and install things. Lucky this was something that is able to be uninstalled and worked on without dropping the whole trans.

 

Wow, this is great. And you’re brave for working on it in the truck. I have one auto 4r and one 5speed and i like them both. Especially like the auto for in-city driving. And zero to 60 they are just about the same.

 

Updates:

A few parts came in...

Filters and spring on the right side.

Fitted the spring I ordered as a new replacement for C-2 accumulator. It is probably the right spring. I really have no confirmation since the one I removed from my trans was turned into metal mulch.
Looks like the set that came out of a supra a340 had a much stronger spring in c-2. That one still fits over the doubled second spring the trans-go kit has you add and the one that was shipped as new for this parts diagram off of partsouq is much weaker. Not a weak spring in comparison to the rest of what came out of this trans though. Really most likely wont have a problem with either but having a more varied spring ratios in the compound spring rate going in that accumulator now will maybe be better in the long run.

On to the filters and o-rings.

Filters were an interesting situation because the ones sent as new parts were vastly different from the ones I removed from the transmission.

This is the filter 1 of 2 for the lower valve body. New ones sent are very clearly a different part. This wont necessarily be a problem because the valve body is made in a way that looks like it allows for this cup shape at the bottom of the new ones. New part means new spirigyness and I think it should probably be fine. Following this is a pic of the lower VB with them installed. They're a hair over flush with the surface. This probably means the revised cup shape at the bottom allows for some compression and pressure fitting against the middle plate for better filtering of material from the VB.

Bolting the VB together will probably allow everything to seal correctly still.



Next is the filter for upper VB.

This filter is very different. from the old ones.


The new filter has a squared profile compared to the one I removed from this originally. It fits into the upper VB perfectly. There is a small recessed portion machined into the VB that the bottom of the filter is clearly made to fit into.

What is even more interesting is the new filter fits THROUGH the separator plate between valve body halves.

In the S of the transtec logo on this gasket is the filter fitting through the separator plate altogether.

I am gonna assume that was an intentional design to create a flush seal for filtering purposes.

Either way this is as far as I have gotten. Torqued the VB halves together at 60 inch-pounds (55 to 62 is the spec). I let it sit overnight and torqued again.

 

Good post Livergang. I only guess that you've done trans-type stuff before? Always a Wizards Black Box to me.
I swapped in a 5spd when I put a 5vz in my 95.
I'm certain there are other threads that I missed but this seems like it should be in the list of keepers.

 

I have never opened a transmission in my life before this one.

I have gotten past the point of being nervous working on it. Maybe because I don't feel super attached to the auto.

If I can get away with all this working on it and have something that still functions once I put it all back together I will be pretty stoked. If its dead I wouldn't be surprised. The great experiment.

I hope posts like this thread show others its not such a black box. Very possible to do work on an auto. Following some of the basic rules can get you far just like any other major service point on a car.

Following specs and procedures, doing research, and cleanliness will go a long way.

 

If a new part differs in appearance then the old one you removed, like that filter, go look on EPC-data.com and research the part. Most likely you'll find the part number has been superseded to a newer number. If Toyota changes something about the original part design they almost always give it a new part number, typically just changing the last 1-2 digits.
Nice work on your part so far. I'm optimistic it'll end well.

 

Progress made lately.

Trans ahas been pulled out of the truck. Unfortunately all the trying to get the splines to line up by just dropping the motor in and praying did not help. Torque converter is buggered up pretty bad.



Gonna replace this ASAP. Couple of options online from JEGS and Cobra Transmission. Cobra one is low stall which I haven't experienced before but also $300 more expensive. JEGS has good reviews as far as I can tell.

Local parts houses were no help finding one. They could send my core out to be rebuilt but no promises they could get it done with how bad the shaft is. Not confident but I am pretty sure it will chew up the seal on the transmission side of things if I try to run it.

Stay tuned.