Transmission gear shifting issue, not hunting or vibration related

To get into more detail, it's basically exactly like the OP explained... relatively coasting after acceleration between 25-35mph, shifting between 2nd and 3rd gear. For me it's only when cold. It's only concerning and extra noticeable for me because it happens at the same spot every day on the way to work when the engine is cold, when I let off the gas slightly for a sweeping turn by my house... it shifts, and between the shift for less than a second it revs higher than it should. I'm more concerned about the lag between Park and Drive, and from Reverse to Drive.

 

The lag between park and drive is "normal" or "common".. Mine does it as well.. Only when cold. If it's not a sign of damage, I can live with it.

So you can reproduce the slip everyday?.. That's great to hear actually.. Especially how you describe it. It sounds like the torque converter is locked/coupled and putting power down, then You let off. So it disengages to allow coasting at the same time you give more throttle and it's shifting, if that makes since..sounds like a timing issue with the shift sequence and torque converter. And the 2-4 gear range would probably be the most common range for this mix of scenarios..

What I don't want is to take it i. and someone crack open the transmission when it's just a characteristic of it...that's even if they see it as an issue..

Thanks for the input.

 

This torque converter is odd...it disengages at speed to coast but the moment you decelerate and get down to around 2nd gear, you can feel it reengage and engine brake (intentionally I presume to help with braking?)

 

That makes sense to me... obviously you know more technically than I do, so it's comforting to hear that you think it's a good thing. I can definitely replicate it at least 4 times a week (of course I tried recording it this morning and it shifted perfectly), next time I'm driving on my street in the AM I'll record a video of the tach and see if I can get it on tape.

 

Mine does the same thing. The RPMs flare about 200 between the 2-3 shift. Mine just started doing this a week ago with 6500 miles on it.

 

"Good" is relative...I like problems that make sense or are repeatable..who's knows if my logic is correct...it could still be problematic or damaging..

 

Yeah mine didn't start much before yours. I even thought maybe it's always done it and I just now started noticing it.. You are explaining the exact same issue. I still don't know if taking it in would do any good with mine being random. How frequent is yours?

 

Does it every morning, well for the last week. Just started. I actually just left the dealership and was talking with them about this. They added a pint of fluid to my transmission. It's overfilled now actually. I'm kind of a guinea pig of sorts for a couple things.

 

Please update with what happens!

Did the technicians feel it and acknowledge that it's an issue?

 

Adding this post to the write up https://www.tacomaworld.com/threads...omatic-in-the-2016-write-up-with-pics.361114/
2 to 3 upshift flare when cold best describes it .
It would be nice to see whats happening on the techstream while you get the flare .Definitely look at the CVI count
You can command upshifts and downshifts with the techstream in an attempt to reproduce the problem .
Considering this only occurs when the transmission is cool , I doubt the flex lock up function is commanded on yet . You need normal operating temps in order for any converter action .
This seems to be a new concern but is very similar to the TSB for the 4 cylinder
http://toyosolutions.com/index.php?...-intermittent-2nd-3rd-gear-up-shift-flare.96/
I would start complaining to your dealers gentleman

 

This is great information. Now to get a reasonable technician to listen to us..

 

And to add some complexity... Mine isn't necessarily when it's cold.. Mine happens most when I've let the truck sir for 30 minutes or so and then leave. Temperature gauge reads 1/3 of gauge to normal temps usually..

 

I see a few of you guys are complaining of the identical problem .
The most likely scenario would be a software fix like they did with the 4 cylinder trucks that use the same transmission .
Dealer technicians dont really get into rebuilding much . They just swap out your transmission for a new one .
This is the first time I have heard of the 2 to 3 flare with the V6 engine .

Here is the TSB for the 4 cylinder .
Some 2016 year Tacoma vehicles equipped with the 2TR-FE engine and the AC60 6 speed automatic transmission may exhibit a shift flare during the 2-3 up shift. Customers may describe this as a momentary automatic transmission slipping feeling. The engine control module calibration has been revised and the computer should be updated with this newest software. See TSB 0079-15

If anyone can find the actual repair info for that bulletin , it would be great

 

This happens to mine. Once a day every day when I leave work.. 2-3rd gear.

 

Mine does this first thing in the morning and only does it once - except it's the 3-4 shift point. When I pull out of the drive and head down the street with light acceleration (it's only 30 MPH on the street) it will go 1-2-3 very quickly and stay in third until around 25MPH and then flare for about a second before going to 4. Once I come up to the first stop sign (about 1 mile) and start again the flare doesn't occur. I've seen other posts similar and comments about the ECM wanting to keep the transmission in lower gears until it warms a bit. I don't know whether those comments are valid or not. As @gearcruncher mentioned above, there is a TSB addressing a similar issue with 4-bangers and the ECM update was for the engine, not the transmission. It wouldn't be surprised if a similar issue exists with 6-cyl trucks but only time will tell if an update eventually comes out.

 

Mine does it as well going into direct drive (4th gear) only once when its cold first thing in the morning . Still no fix for this and Toyota has known about the issue for a long time . My truck is a 2010 model mind you .

Here are the ratios for your 6 speed . Pay close attention to what gear you are in when the flare occurs . Are you guys sure you are in 3rd gear when you feel the shift flare ?
Keep in mind that the initial shift into forward is first gear for the guys who are counting the upshifts . Its better to view what gear you are in using a scanner
2016 Tacoma: 3.91:1 gears, six-speed automatic
1st: 3.60:1
2nd: 2.09:1
3rd: 1.49:1
4th: 1.00:1
5th: 0.69:1
6th: 0.58:1

 

I've noticed this 2-3 flare as well, just does it once then it's fine. Was thinking I may be low on transmission fluid but it sounds like this is more like a ECM issue then low fluid from this discussion.

 

Definitely 2nd to 3rd transition. Although sometimes it catches me off guard and I think I happens at higher gear changes.

Only when below operating temps and under a specific throttle input.

Edit:
They released a new ecm update for the 2016 4cyl AT builds. Do you believe it fixed it or continued the same issue?

Any long-term issues with allowing it to do it.? How many miles do you have on your 2010?

 

I take my foot off the gas and allow the transmission to slowly upshift with my 2010 . I have 120 k on the truck . Doesnt seem to effect the longevity as long as you baby the transmission as you know its going to happen . It is slipping mind you . Any slipping will produce extra wear .
In 2012 , Toyota released a " SPARK KNOCK " TSB which fixed up a bunch of transmission complaints .
https://www.tacomaworld.com/threads...trans-rough-shift-into-5th-gear.260403/page-5
Unfortunately , the TSB was only for trucks 2012 and up .When the 2014 models were released , this was part of the standard ecm programming.
There is a PDF file listed at the bottom of this post for you guys to look at . Its the TSB that fixed up all kinds of shifting issues with our earlier trucks
You can expect to see a similar fix as the TSB above for your 2016 trucks

I havnt heard about anyone on TW who had the TSB update performed on their 4 cylinder 2016 .
I would like to hear if someone had the TSB performed and how much it helped

 

Ok so truck went back in shop today and they checked trans fluid again and this time they found it was 1.5 quarts low! Ok so truck has 9800 miles and dealership asked Toyota advisor about transmission on Tacoma's and he said there is a known issue and told them how to check it. So WTF!?!? Lol I wonder what is going on and if the wrong info is out there for these shops? It is finally fixed and the drive home it seemed same shifting but where I noticed the big difference was on the highway! It did not hunt or shift down and stay in a lower gear with cruise on! I hit a hill and it shifted as it should then dropped back down under 2000 RPM's. Now only thing I'm hoping is that when I call Toyota tomorrow I can get an extended warranty for free! I have ran truck for about 10,000 miles on low fluid!