Best tune for torque converter shutter

Regarding the common torque converter shutter many (including myself) experience at low rpm throttle application, I was curious what tune deals with this issue best? Since Toyota seems to be dismissing this as “normal”, I’m trying to find the best solution before I sell this thing (2021, V-6 with 10k miles). I’ve tried higher octane gas with no success. I recently had KDMax tune installed, and though it’s improved the truck’s driveability & throttle response, it still shutters / hesitates between 45-60 during light throttle at low rpm. It’s maddening. Anyway the tune has slightly reduced the frequency of the issue, as it’s holding gears longer but ultimately it’s still here, especially when going up slight inclines. Just wondering if any of the other tunes (OV or ? ) deal with this torque converter issue specifically or better than my KDMax? Also, has anyone with a 21’ who has the same issue had this resolved from Toyota?

 

Best tune would be to make sure your transmission has the proper amount of transmission fluid in it

 

Get with your KDMax Tuner and see if they can add a custom tune to resolve the issue. There are cases with the 21 we’re this has happened and @PapaRee has done a bit of magic!

 

This helps too! Definitely this!

 

Is this the sensation you get at say 45mph where you feel like the motor has a light misfire? It feels to me like the motor is bogging because the rpms are too low for the gear. Is this what your feeling?

 

Yes this is exactly it. Feels like a misfire. Worst between 45 & 55 at low rpm. Even worse if you throw an incline into the mix. Only way to remedy is to push the gas down far enough to force it to downshift.

 

Buddies 2019 trd feels like the engine is lugging when the rpm are below 1500 in 6th gear. This even happens at slower speeds. I once experienced something similar when coming to a stop with my tacoma when the truck was very new. If you slipped the truck in neutral, and braked it, it wasn't there. After about 1,500 miles this condition vanished, and hasn't come back. Now at 10k miles it runs perfect. Even at 1200 rpm in 6th the truck runs super smooth with decent torque on up.

 

See if can log the data, such as speed, rpms, throttle, accelerator position. Back when 1.05 was released, the issue was with a dead pedal in that speed range in 5th gear. The tune was holding 5th gear to long.
If you narrow down the gear and the accelerator/throttle , you can have your tc locks dialed and/or downshifts to get out of the conditions.

 

What happens if you let off the gas and drop the trans out of OD and into 4 as it’s happening?

 

Dealer here thoroughly checked my buddies trd when he complained about the problem, along with a minor vibration at various speeds. He was told its common for that's type automatic transmission, just the nature of what the truck is. Some trucks its just more noticeable. They did the latest tune, its slightly better, but nothing has changed much.

 

Lol. My dealer said I needed a new transmission. Since they have zero tech support on transmission repairs, they said my only option was to replace it for $7500 with a 12 month warranty, or $6500 for a reman with 6 month warr. They dont do transmission work on site. Except maybe flushes…
I took it to a local transmission shop who charged me @ $1100 to overhaul it, and replace a sticking solenoid and some other stuff .

At the time the issue started, it had 130k. The work was done when I hit 150k.

Dealerships lol, that most certainly is NOT normal for transmissions.

 

anyone ever install a shift kit in the taco tranny?

 

Isn’t that what an automatic transmission is supposed to do; shift for you?

 

Drive in "S5" and you'll see a significant improvement between 44-55. No tune needed.

 

I’m with you OP, feels like it’s just upshifting to soon and keeping rpms too low. I have read in other threads tune improves this and that’s my hope as well. Just hit 5k miles and plan is to tune it after dealer visit.

 

Seems to happen in 5th and 6th gear only. At speeds between 40-60 but 45-55 is the worst. RPm’s need to be less than about 1800. Once the rpms get close to 2k it smooths out. A load (slight hill) makes it worse. Almost feels like it’s bogging down / misfiring and the truck refuses to accelerate until I lay into it and force the downshift. It’s almost as if it’s incapable of maintaining its speed between 45-55 without constantly downshifting. I dread hills - even the slightest of inclines. It like the truck is more than capable but instead of acceleration I just get shuttering instead.

 

I guess i haven't a clue what some are experiencing as i have not experienced any of this with my 2020 v6 auto. If i'm reading this correct...the transmission shutters at 45 mph in 5th and 6th gear? Like i mentioned before my buddies 2019 truck feels like an engine lugging issue if it were a manual transmission if put in 6th at too low an rpm. You could feel the truck bucking. Only issue his truck is an automatic.

 

You said you were on KDMAX tune? "Wife tip" version?
All this can be adjusted , but you need to work with the creator of the tune dial to your DD and terrain. There are no tunes that fix the shudder only. It is a long process of dialing in shifting points, throttle limits, torque request, etc to avoid the shudder conditions.

 

I personally would disagree with calling it engine lugging. With my truck, it's perfectly described as a stutter. I mean the entire drive momentarily stops as if it's running out of gas or even a slipping. It can be quite violent at times, to the point where my coffee has sloshed out of the mug in the mornings..

 

Mat mentioned his theory a while back. Let me see if I can find his post.