20 or 26 spline count convertor

Anyone know which convertor I need and can recommend a brand or vendor? Here’s where the confusion begins. I am unsure if it’s a 2wd or 4wd tranny as it was converted by previous unreachable owner. Since replacing the head it runs awesomely but now the convertor shudder is driving me nuts. Added some Lubegard Shudder Stop and is improved slightly but I would rather just change it. It was making some new unusual squeeking this morning. Thanks

 

Send me a picture of the output end of the trans, and the blue and aluminum placard riveted to the back right corner of the transmission. Should have A340 somewhere in the part number.

With those I or @gearcruncher &co should be able to tell what you need.

 

I know nothing about transmission swaps .
When a Toyota comes into the shop , I always repaired the transmission that was original to the truck .

With this being said , its one of the reasons I created the transmission swap thread .
It was easy to put a write up together showing hundreds of transmission swaps over the years at Tacoma World .
https://www.tacomaworld.com/threads...-4-wheel-drive-or-automatic-to-manual.702733/

Just gotta do some research .

If the converter is locking and unlocking as it should , but shuddering , yah , you have a converter problem but chances are its got nothing to do with the converter .
When a converter begins shuddering , 99 % of the time , its because the transmission valve body is worn out and needs serious attention .
Its just like a clutch in a manual transmission . If the pressure plate becomes weak , the clutch slips and chatters .
The clutch facing on the torque converter gets all glazed up from old transmission fluid .
The clutch facing gets all glazed up because the transmission valve body doesnt send enough hydraulic pressure to the torque converter to hold the lock up clutch applied .
Replacing the torque converter will eliminate the glazed up facings on the lock up clutch , but it will only last a short while before the facings of the lock up clutch begin shuddering again .
You need to address the problem from the source .
When you determine the year of your transmission , Drop the valve body and repair the leaking hydraulics .
https://www.sonnax.com/parts/2764-zip-kit

Edit
For lubeguard to work , you have to change all the fluid , then add the supplement . It will not work unless you also change all the old fluid out.

 

I have replaced the fluid twice within 7mo w/ valvoline max. The magnets and pan were clean. The convertor is actually squeaking occasionally. It has 230k on it. I’m not an automotive transmission mechanic but have into many commercial grade automatics in heavy machinery and marine apps. It seems to me the convertor is likely worn out, there are plenty of wearable parts in there. And since that Shudder Stop, (I swear to God) actually improved it, especially on slight grades, it kinda verifies it. If it was valve body or pressure related, clutches would slip, among other things..obviously some pressures are adjustable but it was designed to operate at the set pressures.... i think anyway... But I will certainly look into the valve body while into it and thank you. I will crawl under tomorrow and see if I can find some identification on it...

 

Will do. Thank you

 

The most common wear area on an A340 series transmission is the torque converter lock up relay valve in the valve body .
Converter shudders occur from the re-agents in transmission fluid breaking down or contaminates traveling through your transmission fluid . Contaminates work like sand paper on your aluminum valving .
The only way to prove my point or yours is by running a pressure gauge on the transmission when the computer commands the torque converter clutch to apply . You will be able to watch the pressure drop as the converter clutch applies
There are many wearable parts inside the converter .
I am not saying that replacing your converter wont help , I am saying it wont last without re-sealing the hydraulic integrity inside the valve body .
The shudder stop assists with deglazing the converter clutch mating surfaces .
We use lube guard Red for the A340 series transmission . It will work better than the shudder stop

 

I appreciate your time and wisdom, I spent hrs reading your threads last night. My thing is the audible noise. I am 100% certain it’s coming from the convertor area, during decel and occasionally at idle. The bolts are tight and correct. Here’s the thing. I don’t have a lift. I gotta crawl under it and don’t want to tear apart things apart more than once. Do you recommend I buy a new valve body and convertor? Better yet, tell me what you would throw at it. I only want to screw with this once.... I am still recovering from replacing the head.. gonna add some “red” tomorrow, saw it on the shelf

 

Ha
Put me on the spot lol
I hear you . Not fun crawling around on the floor . I get it .
With 230K on the transmission , I would expect to see a lot of wear inside the valve body .
Tacoma World is a forum where we all try to save each other money by repairing components ourselves rather than paying triple the price for lesser quality workmanship at a garage or dealership . If you want it done right , you gotta do it yourself

Doing it right the first time is what we are all about at a fraction of the price .

What would I do ? my circumstances are much different . I would go through the transmission .
If I were you , remove the serpentine belt to guarantee the noise is coming from the front of the transmission . This eliminates any chance of a noise transfer .
After I verified the noise is truly coming from the front of the transmission , drop the transmission, replace the torque converter and install a Zip kit in the valve body .
Thats your cheapest bet .
A converter will cost you $200-350 and you give them your core
A zip kit for the valve body will run $200- 300 bucks
If you are not worried about money , there are obviously more options available to you
I do have all the transmission manuals available as well as a factory repair manual for your truck .

 

I follow you and probably exactly what I’m gonna do. Finding resonable, reputable shops around me is tough. I trust myself. lol, 7-800 bucks and some aggravation, problem solved. I will reach out to you after I determine what is in there. Maybe you can suggest a vendor and brand. Over and out. Good night