Transmission issue? Not sure.

2015 DCSB V6 5AT. Searched with no luck, but I did see the thread about the low trans fluid from the factory.

Anyone have an issue with their truck halfway downshifting and then "deciding" not to and remaining in the gear it was in, resulting in a "clunk" and slight jerk?

It happens on slight inclines at low RPM in 5th with a modest increase in pressure on the gas peddle/acceleration. It considers 4th for a split second, doesn't fully go into 4th and drops back into 5th. Does not happen often and I ignored it the first few times, but after it happened yesterday, I was able to recreate it today. It has also happened once with 4th/3rd gears.

I'm under warranty, so I'll take it in with my free service and will have them check the fluid. I'm not confident in my ability to do that.

Is it getting damaged during these occurrences? Is this a typical symptom of low fluid?

Any help or advice is appreciated.

 

Oh yeah... 19,xxx miles, no other issues to my knowledge.

 

My truck does this sometimes and I know it has plenty of trans fluid. My brothers 06 does the same thing. We both run 33" tires, I was thinking it might have something to do with that. Interested to hear if anyone knows.

 

Stock tires and wheels here.

 

I get this sometimes and chalk it up to the torque converter locking/unlocking. That and these transmissions can never find the right gear under load or grade.

 

this.

 

Has this done it for the whole life of the truck?
I have about the same miles on mine and thought there was a problem due to a couple of rough shifts but figured out it was Toyota Tacoma Transmission Hypochondria due to reading about the 2016 problems.
Trans reacts to gas pedal input and angle of road you are on and does things that we don't think it should.
Never read anything here about the Gen 2 ever not having enough fluid from the factory.

 

Agree with those who mentioned torque converter.

My first car that had a locking torque converter had me thinking that I had a 4 speed tranny when all I had was 3.

 

I think I'm talking about something different. What they are describing in this thread: https://www.tacomaworld.com/threads/auto-tran-d-is-two-gears.161963/ is not what I'm talking about... when the TC locks up and you get a little boost in 5th without downshifting like at 70mph. Like I said above, it feels like it is trying to actually downshift to 4th...does it partially for a split second, then up shifts to 5th again, but the result is a clunk and a jerk. The best way to describe when this happens is at low RPM in 5th, 40-45 mph, slight incline, and that in between pressure on the gas pedal between getting it to downshift and just using the available torque in 5th at that low RPM. Does that make any better sense?

 

Fifth gear, 40-45ish, slight incline, and light throttle input are literally the gray areas of the tranny and torque converter. Could be 5th gear torque convertor locked or unlocked, or 4th gear locked or unlocked. I think the clunk and jerk are the result of these components becoming 'confused' for lack of a better word, and then making an abrupt 'decision'.

I think I may know what you are describing now. I drive in similar terrain and speeds and may have experienced this, but figured nothing of it. Will try to recreate tomorrow.

 

It sounds like you understand what I'm saying. In the end, I'm not going to freak out about everything, especially since I know taking it in will result in not being able to recreate the issue. I just want to know if I'm tearing it up when this happens, which is about 10 times total. I've been able to create it twice. But yeah, it definitely feels like a confusion as you describe.

 

Mine does the same. 65k on a 2013 always done it. Annoying...

 

my 15 has done it since day 2. Didn't do it when I test drove or signed loan papers. Toyota is slick I'm in pretty flat Florida and yes it is annoying for sure.

 

Had same problem, drained tranny from drain bolt at bottom of tranny pan, only 1 qt came out, replace drain bolt and tourqced, fill with 3.2 qts of WS ATF Fluid in filler plug hole with a pump. replaced fill plug and retorqued. Run and test drive for 100 miles and no problems any more, was low on ATF fluid, Problem resolved for very little money, try this before wasting big bucks and tranny damages! ASE Tech for heavy diesel trucks ,dozers and all heavy equipment since 1976. Your welcome!

 

Procrastinating the atf level check............... I'll call Toyota and complain of shift issues and point in the direction of low levels from factory, request a level check and go from there.

 

Not to sound like the dealer, but I drove around for about 15 minutes in hilly-ish areas today and could not duplicate the problem. Was in 4th and 5th gears, torque converter locked and unlocked, purposely feathering the gas and nothing. IIRC this happened to me at higher speed so may test that out later.

 

This is normal. The A750 trans is not buttery smooth. However, it has a known long service life.

 

Thanks for the responses everyone. I'll carry on for now, get the level checked, and see what happens. I have the extended warranty, so I won't lose too much sleep.