2004 Tacoma - Weird transmission issue

Hello all.. first about my truck:
2004 Tacoma
V6 3.4
4X4
Auto transmission
Xtracab
55K on the ODO
Bone stock
All service up to date

I just recently started having this problem, as in the last few days. The truck will work just fine in 1st, 2nd, and 3rd gears, but every so often when it goes to shift into 4th gear (overdrive I think) sometimes it the RPM will vary by about a couple of hundred and it will hesitate to shift into overdrive. Almost feels like its slipping, but after a few second it shifts into overdrive and all is good.

Then every so often while driving on the freeway 65ish (about 2100-2200 RPM) all of a sudden the RPMs start to fluctuate again and you can feel the truck sort of "stutter" for the lack of a better word. It will go through 1,2 and 3 just fine, no issues whatsoever but 4th is a different issue. Also it's not like this is happening 24/7, sometimes it does not happen the whole trip but today it did it three times on a 20 mile drive.

First I though the trans fluid may be bad, but it was pink and did not smell burnt and had just the right amount in. In any case I did a drain and fill but it did nothing to improve the issues.

I searched on Google and there are plenty of discussions for different cars/trucks (anything from torque converter, TPS, MAF etc), but was wondering if anyone here any any better ideas on what my truck is going through.

Thanks,
Dan.

 

Does this also happen when you disable the over-drive using the button on the shifter ?

 

No it does not. When I disable the overdrive using the button it never gets to that gear and never does it. I have only observed it when it is in overdrive, as soon as I turn overdrive off on the shifter it works just fine other than the engine reving quite high for highway driving.

--Dan

 

Shoot sorry to hear about your issue. It sounds like OD may be on it its way out, or the transmission itself.The fluid may have been changed prior to purchase.
My first thought is the truck may have been used for towing. If it was, and it kept searching for a gear (in and out of drive and OD) it creates excessive heat within the torque converter. In which case can cause premature wear and failure. I may be jumping to soon, let's see what others say.

 

I have owned this truck since it was brand new, I forgot to add this. In its life it has towed a 400lb motorcycle and 300lb trailer 60 miles, the rest of the time basically it has been just driven without anything attached... the hitch has been used once. Now I have hauled stuff in the bed of the truck (TVs, gardening etc) but never really got over 300lb in the bed.

This truck has had a easy life I think, rarely does it ever go past 2500rpm and I have never missed a service. Just kinda disappointing to me that after 10 years and 55K miles the trans may be on its way out.

--Dan

 

I'm no expert on these computer-controlled automatics, but it may not be the tranny itself.

Pretty sure that sensors tell the ECM when to upshift and downshift, and it sends signals to the various solenoids inside the tranny. Do some googling on this. It may just be that one solenoid (replace-able?) that controls the OD is bad, or perhaps one of the sensors feeding the ECM.

 

Hi All,

First Post...

(almost) Exact same thing is happening to mine.

Bone stock 2002 double cab v6 auto tranny 152k

On the highway at 50mph in OD I get a 'stutter' it only happens when I am trying to accelerate, if I am at a steady state it is fine. Using the PWR ECT button seems to help and obviously when I use the O/D button it goes away entirely. This truck is new to me, I don't know how it was used, fluid was a little low, I topped it off and it made no difference. Truck runs fantastic otherwise and 4wd and diff locker work great. First 4wd toyota I have ever owned and I am in love.

 

I made a video today of what I am talking about.
The first part of the video shows normal operation going through all gear merging onto the highway.

The second part is shows where the "stuttering" happens. This was all with the same gas pedal pressure, I never hit the accelerator pedal any more to accelerate faster.

Sorry about the noise every time the truck went over a bump, I had a home made mount and it was very loose.

--Dan

 

I found it interesting that it did it right when you turned on your turn signal. Have you checked your electrical connections at the battery and main fuse block under the hood? Just thinking outside of the box.

 

its almost timed perfectly with the turn signal

 

That was just s coincidence. It did it 10 minutes later without changing lanes and using the signal. Usually when it does it I'm cruising on the highway without lane changes.

--Dan

 

Although now that I think about it it could be timed with the turn signals, I may have been changing lanes every time I realized it happen... I will have to go out for a drive here in a bit and test the theory.

--Dan

 

To me it feels like the torque converter is locking and unlocking repeatedly in quick succession, My situation is unrelated to the turn signal.

 

I have had ford trucks my whole life and this happens to them with the e4od automatics they are also electronically controlled. I can almost say for sure it is a bad sensor, switch or something electronic. I don't really know much about toyota a but it sounds similar to a common ford issue

 

I can't watch the video bit my first assumption from your description was the torque converter clutch...

 

I was thinking the TCC which could be a number of issues. That was my first response I typed, but then the turn signal just seemed weird. The 200-300 RPM drop could be the TCC. It could also be a slight misfire under load. Do you know anyone with a code scanner that can check to see if there are any stored codes?

Does the condition happen if you drive a bit more aggressively?

 

You guys were dead on, I tried the theory that it only does it with the indicator on and it exactly what happens... It only happens in overdrive and with left indicator, the amount of acceleration does not matter one but, light acceleration as well as hard acceleration same thing.

I made another video to show this... now what in the world could be causing this with only the left indicator? The only thing recently I changed was the dome light bulb, but that was about 8 months ago... since then absolutely nothing has changed on the truck.

I guess tomorrow I can start changing the indicator bulbs from left to right see if the problem moves with it. I am not very good with electronics but if anyone has anything I can test / try please let me know.

At lest now I know how to re-produce the problem if I have to take it to the dealer to find the problem.

--Dan

 

I have a scanner and there are no codes stored. Does not matter if the driving is aggressive or not same thing. I have not tried to really step on the accelerator to see if the issue persists.

--Dan

 

So when it does this, you can feel a surge or are you thinking it's there because of the tach flutter? I'm trying to understand if it's an indicator issue or if it's an actual drivability problem. Do you have access to a volt meter? If so, I'd check the battery voltage with the right and left turn signals with the ignition on but the engine not running.. See if possibly the left is drawing the battery down a bit more - could indicate a high resistance in the circuit (dimmer lights by chance?) or a short. It may not be enough draw to register on a DVOM, but it's a thought. If you take the left turn signal bulbs out, does it still do it at highway speeds? If so, I'm wondering if you have a short between two wires in the harness somewhere. When the left turn signal circuit is energized, it could be feeding 10-13.7V into an adjacent system. I don't think it would be a ground.

Let me know what you find. I work for ALLDATA, so I can pull up the diagrams for the truck or talk to our master diagnosticians tomorrow.

 

does your cruise control turn off when you hit your blinker ? I had the exact same problem and it ended being a bad wiring harness for my trailer plug. 99.9 percent sure this is your problem