Best tune for torque converter shutter

With every automatic I’ve owned I have tapped the throttle to trigger a downshift before trying to accelerate or go up an incline. If you simply apply a tiny bit of throttle slowly, autos tend to stay in the same very high gear and bog down. The one thing an auto cannot do is anticipate your next move.

 

Same here. It often feels and sounds like driving over very aggressive highway ‘rumble strips.’

 

I do the same to save on the brakes when going down a long grade. I have zero issues with my automatic when going up hill. I don't even need to push the accelerator pedal down further, but keep it steady, and the transmission will downshift automatically when it senses it. You can then press the petal harder if you want to go faster just like any other automatic vehicle i've had. I would think a sensor in the transmission is faulty if you have push the pedal down to make the transmission downshift when climbing a hill...imo, its not suppose to work like that.

 

Wow, thats quite a bit different then anything i've seen. Never experienced it it any toyota automatics i've had, or been in. Sounds more like a bad transmission.

 

I have experienced this as well on my 2021 Taco. I previously had a 2020 Ram 2500 Hemi.
When it went into MDS at low rpm if felt quite similar. My resolution was disable MDS. My resolution on the Taco is to add enough gas pedal to have it drop a gear to keep the rpm up. I am under the impression that at the lower rpm the 3.5 is in it’s akinson mode and when put under a load it feels like the MDS did under load.

my .02

 

I didn’t have any issues with the AT in my 2016 either, but being an auto I found that it didn’t always downshift as fast as I wanted so I frequently coaxed it with a quick throttle tap.

 

I never have to tap the throttle going up a grade, only to save on the brakes going down....been that way from day one.

 

Fwiw, this is near identical to issues with the FJ transmission that ultimately ended up being a TSB transmission replacement (or perhaps repair). Right rpm and right load(light) and I could get it to shake really bad. One of the senior techs I took for a ride said ‘head back, I know exactly what this is’. He thought it was really loose lug nuts and the tire wobbling badly.

If I took the FJ out of drive, it went away immediately and was not reproducible. I could force it in nearly any gear. I downloaded an app for vibration analysis and it had a pretty sharp peak that was consistent across the various gears.

In the end, my subconscious just learned to give it a little more gas (or less) around the prone zone and I lived with it from ~60k miles to 190k miles.

It was definitely a torque converter issue. I think it had something to do with tolerances and locking/unlocking.

 

Put your foot into it. Maybe I drive like a maniac. I have not experienced any trans issue on my 2021. I don’t lightly apply the gas. I push the pedal, not to spin the wheels, but I push it.

I wonder if some folks just lightly push into the pedal and that brings on the shudder. Get into it folks. It needs gas to get the converter spinning. Don’t try to gently accelerate, give it the gas and then let off, do it in reverse of what you are use to. Maybe that will work for you. Slam it down and slowly let off as you start to move. I think everyone’s issue will go away.

 

It wasn’t just acceleration for me. It could be steady state speed with a light load.

 

Makes sense. I still contend it was a torque converter issue when my 2020 auto sr5 was very new and had a slight shudder when coming to stop. When i slipped the transmission stick in neutral and applied the brakes it was no longer present....reason for figuring the converter. Once the truck accumulated over 1k miles it was no longer there, and hasn't returned. I just chalked it up to these parts breaking in.
Its a different story with a buddies 2019, he still has that lugging issue which i do suspect its in the transmission from not receiving enough torque from the engine.

 

Sorry, I should have been more clear. It was definitely related to the TC, albeit wrapped up in the transmission package.

 

Try putting the tuned truck in S6 (it will auto up and down shift for you)... See how it feels.

 

On my truck there is no S6, only goes up to S5. I have to go back to the D mode for 6th gear. Been that way since new.

 

Like you visually can’t see S6 on the instrument cluster?

That’s maybe something the dealer needs to look into.

 

No S6 display, only up to S5. Idk, truck runs really well. I'm one of those guys that let a sleeping dog lie. Besides why would toyota want you to use S6 anyways?....makes no sense. I've always figured its done this way on purpose.

 

My 2020 TRD Sport has the exact same shutter at 45-55 mph in Drive. It feels like its locking and unlocking repeatedly, creating the slipping sensation…. Approaching a small grade while cruising through traffic makes me cringe. The dealer says all is normal.
I’d love to find a fix. Checked the transmission fluid the 2nd day I owned it.

 

I just got my truck KDMAX 6.0 tuned this last Sunday. I am not feeling that shutter or miss feeling I was before. Even my wife noticed that it was gone. Only have 80 miles on the tune but seems to have addressed the issue for me.

 

S6 is auto. no point in using s-6 as that would be the same as D

 

Not quite. S-mode has completely different shift, throttle, and torque converter lock/unlock settings from Drive, different axis systems, different curves, etc... It’s actually significantly different when you look at them in vFTuner.