Another 3rd Gen torque converter issue?

^^^this^^^
OP, most of us know what you're talking about with your situation. Try ECT on, and/or s4 and s5. She likes to shift quick and stay in a high gear, its probly halfway lugging to scratch out more fuel mileage. Ironically, I get better fuel economy at higher rpms. Guess it's less strain on the engine, apparently.
In short, dont worry about it. These trucks can be a little quirky. IMO they drive so much better when you give it the beans and and drive balls out.

 

I don’t feel like reading through 5 pages but does the vibration go away when you switch to 4HI?

 

He said the ECGS bushing is already done. Right in the first post and several other times throughout the thread

 

To solve this you are going to have to find a tech who can actually diag without having their hand held by toyota. Running a datalog and watching when it happens and see what it is doing. Without going into exactly what to watch or writing a lengthy post if there is anyone who is willing to make a drive I am willing to run a datalog and see exactly what is going on. With all the posts about this I have never seen anyone actually show exactly what is happening. I am willing to put this to rest if someone will bring a truck with a known "torque converter shudder" to me and let me diag it.
I am in Macon Ga

 

Should I make no further progress, and end up going over the 60k, I’ll gladly make the trip to you. Just to get it diag'd and on paper. Since I’ll have something already on record with them, this could help as well.

I’m in Spartanburg, South Carolina.

 

Understood. I am heading back to the dealership to have them ride with me and stream data live. We will flag every time it occurs. I’m far from giving up.

 

mine shifts like crap too and i got tons of vibrations and clunky shifts so let me know what fixes it. sometimes it seems to get better for a bit, then gets worse. tried doing a drain and fill and it helped for about a week then seemed to get worse.

 

I've been using obd2 monitoring since 2018.
Even on some tunes it locks up at 40 on the freeway on-ramp.
oem settings for tc full lock in S4 map is the same as D4 map


Here is locking up TC at low speed (30mph) at 3.5% of throttle on some tune

 

I'm voting TC shudder that on now more pronounced after bigger tires and lift. Adding even a slightly heavier tire to the truck will put more strain the drivetrain. It might have been just enough to make the problem more apparent.

 

Lift and tires aren’t new. Lift and tires are well over 20k on them.

 

Back at Toyota as we speak, boys.

About to hookup the computer and go for a little drive. It occurred the whole way up here. I haven’t even shut the truck off, I’m just waiting for the service manager and foreman now.

 

I have done it back in 2018. In techstream, I was watching solenoids status, temp etc.
When it started shuddering, the tranny temp would jump by a few degrees. Evidently tc was slipping.There were no changes in the status of solenoids.
Also, there was a theory on vvti angle fluctuations. I have not seen it.

The rumor is that TCU have pressure settings that could be adjusted via vftuner. However I cannot see the pressure settings via techstream.

 

Can you explain those graphs in the 1st pic? Speed is on the X axis and what is on the Y? Engine load? In which case everything under the curve is locked up, including all the way down to 0 speed?

Also is the 3rd gen on/off lockup, or does it vary with PWM? The data log says off, on, and on-on

 

Were you able to log tq duty cycle and slip?
Need to see rpm fluctuations of the engine and output rpm of the trans.
I agree that a rise in temp is usually associated with a slipping converter.
I have been dealing with slipping converter for years on older fords(4r70 trans) and newer chevys(6L/8L) the chevys are easy to diag by watching the converter duty cycle and converter slip rpm.

 

Update

Toyota has a TFST (Toyota field service tech?) coming tomorrow to look at another Tacoma with a transmission issue. This issue is far worse than mine.

They offered to put me in a rental overnight, so they can have the tech look at my truck, but he said he’s not sure what will come out it, and didn’t want to get my hopes up.

He advised that he does feel something, but does not believe it’s outside of tolerances. He advised “they all do it”. I asked if I was reading into wrong, is something else connected / to blame? He advised that he’s not sure what it could be, but is confident the trans is fine.

They checked over the induction system previously, assured fluids are at level and are clean as a whistle. No metal shavings found on the plug, but they did not drop the pan.

It did not show any dead miss : misfires in general during our drive, even while the issue was reproduced and flagged.

I drove a 2020 model equivalent. It rides smooth, brakes smooth, but there is a similar, albeit more subtle, feeling. So he advised that because of tolerances.. and the fact that I felt something similar that there won’t be much else to do.

I do truly feel they want to help, but I also agree that without it being more… aggressive in its duplication, that they can’t (in their words) “chase it”. Toyota basically tells him, the foreman, that something’s are what they are. If there is an evident problem, it’ll be replaced no questions asked, but in my case… it just kind of is what it is

He advised that if I should have a failure within 10k of reporting the issue, since it’s been two documented instances, it’ll be covered… that’ll be determined should it happen if course.


So that leaves me wondering… if not the tranny/tc, what else? I guess for now, I’ll never know. I’ll be sure to update y’all should something fail. I love this truck, I’m going to keep it. It just.. no longer gives me the same excitement to hop in and go, and that’s pretty disappointing. I know I know.. “it’s a truck” but again, it wasn’t doing this before, and the gear hunting never bugged me. So.. for now, I’ll accept the fact that it drives like my 1985 S15.

Maybe I’ll do the carrier bearing spacer anyway. I have the kit, but only being lifted 2.5”, I’m not sure it’ll do a thing.

Thanks to everyone who chimes in, thanks for helping the best you could.

Yes, I’ll still be doing a drain and fill. Although, I have heard that could make it worse. If I’m going down, I’m going down swinging. At least if it’s worse, perhaps they’ll be more inclined to tackle it. IF the transmission was to blame regardless.


Oh… one more thing. I cruised in s4, and s5(Highway). Issue remained. If that matters to anyone out there.

 

Agreed...take a snapshot of the AT.,,this is a Honda snap
https://youtu.be/-2RXOdTRHVk

 

Throttle position.

 

Just a thought (though much better to know exactly what's going on) have you considered a regear? That'll keep your rpm higher. It might just move the shudder to a lower speed, but it's possible it might just get rid of it too

 

Techstream does not have tq duty cycle PID under TCU.
I was looking at Output shaft and NT rpms. I'm going to pull some old logs to find the condition

 

A drain and fill will not hurt the transmission at all its good to drain and fill at least every 50k miles or so. If its dark looking I would actually do it once put 3 quarts in drive 100 miles and do it again two more times for a total of 3.