A340F advice - 2014 4x4 'shudder' NOISE (this is different!)

Hoping to hear from Gearcruncher and others -

Short story version: Reg cab 4x4 2.7L with A340F (assumed)
3" lift, 265 tires
Has been in an fender bender, no major damage noted
Bought used, no history. Has 50K (90000KM) on the odom.

Day I drove it home, problem was there (2 years ago now).
Hot only (15min drive), in 3rd or 4th at engagement and light on throttle
And now on 3-4 shift at 60mph, but for only a very short duration

There's a vibration/shudder that shakes the entire truck
It isn't so much 'felt' as it is heard

RPM is steady during the condition, no DTC
Fresh fluid, tried LubeGuard instant shudder fixx

Lock up is annoyingly in and out on this machine at hwy speed, not sure if this is part of issue, or just a characteristic

The problem is : light throttle, 30MPH (50KPH) 3rd gear - noise/vibration is there for only a short moment, might be able to make it stay noisy by feathering the throttle, 5 seconds or so, until it drives over or under that speed (RPM is around 1300)

Again, light throttle, 40MPH (60KPH), 4th gear - noise is identical in rhythm/intensity but much easier to modulate throttle to keep the vibration there. Still around the 1300RPM mark. I can hold the speed much better and the vibration will kick in and out, but still last several seconds and up to 30 seconds if I hold the throttle just right.

Loaded the bed to change driveline angles, loaded trailer for torque, no change at all.
Replaced the fluid, added the LubeGuard, no change.
Reset the ECU (shift adapts), no change.
Fluid isn't burnt (but was smelly when I bought it 2 years ago).
I've run it on this fluid over a year now, but I don't drive it much.

This week, I drove it with the transmission electrical connector disconnected - no more noise/vibe!

If I were to guess, it could be a sol that is not powering up properly and fluttering, or maybe even low fluid pressure. I'm assuming that if it's signal OUT, then the PCM is happy with the info because it doesn't code. TPS? Bad ECU? Bad sol?

I want to do a resistance check on the sol, but with the connector facing up, I can't see to probe the terminals.

Diag - what else can I check, what part could I throw at it as a best guess..
Is the valve body difficult to drop and will parts fall out everywhere? I'm not crazy about chasing check balls and trying to figure out where they go.

Any help or ideas are appreciated.
I'm about ready to sell it, as I'm not enjoying it.
I really love looking at it, but I'm tired of driving it

 

I should mention, I don't feel there's any value in going to the dealer with it. I'm sure they'll tell me it needs a transmission (which I'm fine with, IF it does).
I don't trust the local transmission shops either...
I have the knowledge to replace the trans myself, if I can figure out the right part from the bone yard... although, they don't have many of these, maybe not any.

 

@gearcruncher
If you tag him, he is more likely to see your post. Good luck, transmission problems are always a pain.

 

Sounds like a torque converter issue or possibly engine issue to me .
More diagnostics are needed for this conclusion mind you .
I would start with a brake tap test .
Overhaul / troubleshooting manual is at the bottom of the first post .
Run through some diagnostics , then we can look at a couple possibilities
TRANSMISSION SWAPS - Convert to 4 wheel drive or automatic to manual | Tacoma World

 

I don't think engine... no DTC? I replaced the plugs just in case, ran some fuel conditioner. No change. And with mission electrical disconnected, no issues, so I think not engine.
I don't think TC either, since it seems to do it early in the shift. Once engaged, works perfect. The lubeguard didn't seem to make a difference.
So I got away from TC, when it started acting up on the 3/4 shift at higher speed. At 100kph, when it's undecided whether to be in 3rd, 4th or lock up, the vibration only seems to occur on the lock up to 4th, or 3rd to 4th shift. But it is only there for a second or 2. Same intensity, same vibration/noise. I'll look at the diag, but this has ETCS and no cable to the mission. The electrical disconnect seemed like the only diag I could do.

 

oh.. brake tap.. NFG - vibration still there, and goes into brake overide before I can figure anything out and the vibration is gone. As soon as I'm off the throttle (physically, or demand by PCM), nothing truck is normal.

 

I'm not sure where the diag you are referring too is in this post? Or did I miss the hint and should just put a stick in it? ;-)

 

Sorry that was the incorrect link .
A340 diagnostics are under my user name posts I have created .
I am wondering about the condition of your flywheel .at work now .
Let me think about this some

 

I've followed your links for the diag... but I think it's for an older version of the 340F. It has the throttle cable that can be adjusted, mine has no such cable.
You have me curious with the flywheel.. not sure how that would come into play.

Your first reaction to possible engine side issue tells me you understand the condition - If it had a bad ignition coil, that only failed under light load and in 3 or 4th gear, it would be very similar. And if it was a grounded body mount with that coil, even closer to the condition. But with no DTC, no misfire, no lack of power, no slipping... it's not that (or it shouldn't be that).

On that same token, if the linear sol is supposed to pressurize the ckt and it fluttering (bad coil, ground, etc..), maybe? I even wondered about a cracked valve body? Pressurizing the wrong ckt when hot. Likely wouldn't set a DTC. Command from the PCM is happening, so it won't code.

If the gear change occurred 5-8 mph later, you wouldn't even know there's a problem. The tires are only 1 size larger, so ratio is not likely a problem. GPS says my speed is spot on with the speedo. Tach does not fluctuate during the condition either. I'll try to upload a video - but if you imagine all the loose change in the cup holder rattling at the speeds mentioned, that's what it is. You hear it more than you feel it... and it rattles the change pretty good.

 

I found my videos, but not sure if I can upload them to this forum? Anybody?

 

Tried to zip them, but too big
If you want, I can share on Signal or messenger, unless you know how to post to the forum

 

Here is the link I was trying to send you lol . Sorry about that .
https://www.tacomaworld.com/threads...sions-write-up-your-4-speed-automatic.325531/

If the issue goes away when you disconnect the wiring harness feeding the solenoids , we can begin targeting overdrive and the locking clutch as a " symptom" of the vibration , however at this point in diagnostics , I still think you have a miss fire undetected by the computer in your truck .Engine misfires are a common occurrence with no diagnostic codes . Seldom will you get noise along with a vibration from a faulty converter clutch .

Before I jump to conclusions , lets verify for sure You are performing a brake tap test correctly . The idea behind the brake tap test is to verify a torque converter shudder .
The truck must be warm before the transmission will upshift into 4th gear as well as converter clutch activation .
Take the truck for a burn on the highway to get the converter to apply .

Watch your tachometer for converter apply . RPM should drop by 300 rpm
When the converter is locked and you begin hearing and feeling the vibration , hold your right foot steady on the gas pedal and gently tap the brake pedal with your left foot . You are not actually hitting the brakes but a gentle tap of the brake pedal triggers the brake switch . When the brake switch is triggered , the computer in your truck thinks you are coming to a stop and commands the torque converter clutch to release .
If the vibration goes away when you gently tap the brake pedal with your right foot while maintaining speed with your left foot ,you need to look at a possible torque converter issue . As soon as you release your foot from the brake pedal , if the vibration comes back , the converter or an engine misfire are to blame .
If the truck continues to vibrate while you gently tap the brake pedal , Its not a torque converter problem .
Lets start with this

Once we get this out of the way , we can try reproducing that vibration / sound without moving the truck if things progress.

 

Thanks gearcruncher - I'm 99% sure that the vib is still there after tapping on the brake pedal. The RPM will climp, the vib remains until the PCM pulls power for the Brake Override. But I'll check again to be 100% sure.
I'm shocked that the ECU wouldn't pick up a misfire?!! I have a generic scan tool coming this weekend, and I have the Toyota software if I can ever get it to work on my laptop. I'll test again. And I honestly wouldn't be shocked to find a bad ignition coil, although it's not an easy one to diag.

 

If your loose coins are rattling in your cup holders , you have some serious issues . At this point in diagnostics , I do not believe its a transmission issue .
Take a peek at my vibration thread as well .
There are some possibilities that need to be eliminated before we call the transmission the black sheep
https://www.tacomaworld.com/threads/vibration-diagnostics-for-all-tacomas-write-up.520607/

 

Universal joints - Vibe is only in 3rd or 4th, at 30 and 40mph (respectively), and again at 60mph on 3-4 shift
Have you greased your driveline ? yes
Have you slid under the truck and inspected to see if any driveshaft weights have fallen off ? all good
Have you checked your carrier bearing - yes
Does the truck vibrate in park or neutral and does the vibration change with accelerator pedal ? no
When was your last tune up ? Fall 2020
Does the truck vibrate while holding the brakes and hitting the gas - Automatic ? no
Does the truck vibrate in neutral at a stand still ?or coasting in neutral ? no
Does the truck vibrate in 4x4 ? Will confirm, expect no change
If you are 4x4 , you can remove your rear driveshaft and test drive with just the front driveshaft to see if the vibration is gone - will try, but not expecting change
Is your truck cold or warm when you feel the vibe ? warm/hot
Does the truck " Only vibrate " from 1st to 2nd gear ? no
The dreaded ECGS bushing - Does the truck only vibrate in 2 wheel drive ? I will read this post and confirm
Does the truck vibrate with the serpentine belt removed ? not applicable
Does the truck vibrate if you select neutral and coast to a slow roll without using the brakes ? What happens when you turn the truck off in Neutral at highway speed ? Can you still feel the vibration ? As soon as I'm off throttle, gone
Does the truck clunk over bumps ? no
Does the truck vibrate as you are braking ? no
Does the truck vibrate with weight in the truck or empty ? Hows the leaf springs ? no change

Does the truck vibrate while upshifting ? Have you checked your trans fluid ? yes, clean and clear
When was your last transmission fluid change ? did you use WS compatible fluid ? A340F uses Type IV I think? need to recheck, replaced with recommend fluid
Does the truck vibrate while downshifting ? Have you checked your trans fluid ? no

Is the vibration caused by your torque converter ? Can't be sure
Are you a victim of the flex lock up issue ? 2nd and 3rd gen Can't feel it in 2nd
Now that you have a lift kit installed the truck vibrates . Did you cancel your drive line angles ? Loaded box, no change
Have you looked at the condition of your body and frame mounts ? yes
Have you looked at the condition of your tires ? yes
When was the last time you rotated your tires ? 2x a year
Are you using LUG centric aftermarket wheels that are incredibly difficult to balance ? have you considered " HUB centric rings " - installed

Have the balance weights fallen off the tires ? no

A good vibration technician can tell immediately if your vibration is caused by the rotating speed of your wheels or by the rotating speed of your driveshaft . It is not a tire vib, I'm sure of that

 

Anybody know how I can share a video? @gearcruncher , want to pm an email to send them to you? You have to hear this
I originally thought it could be a coil that was failing, but the fact that it only occurs under the very specific speed/RPM and gear just doesn't add up - but it feels just like that.
It doesn't feel like its slipping, nor does it feel like a driveline vib (tire, d/shaft, etc...).
If you told me the sol that controls lock up was weak, had a bad winding, I would believe that. If it was low press (low RPM, pump issue, bad programing, restricted filter), I wouldn't be shocked.
The intensity of the vibe can be modulated with throttle application (sometimes it's really soft, other times it's almost violent). But the speed of the vibe is consistant, regardless of gear/RPM. It doesn't last long - if you're on the gas, you'd never hear/feel it as it goes from 0 to 100. It will be there on a 3-4 shift at hwy speed (cruising up/cresting a hill).
On a country road with a 40mph speed limit, light throttle - it comes on at 30ish mph in 3rd. That one is hard to keep in the zone, it wants to shift soon.
Cruising light throttle at 40 though... starts around 38mph ini 4th, seems to phase in/out 3 or 4 times. Get to 45, totally gone. Go back to 38 and accel lightly, starts all over.

 

Easiest way is to post to youtube and share the link, you just have to make sure it's not set to private video.

 

DOH! Thanks
https://youtu.be/Sq_pNi99aQ0

https://youtu.be/_g5y76LrKaA

 

So at 40, if it drops to 3rd, vibe is gone. That 12-1600RPM seems to be the only time, and you can only do this with a light foot. It is annoyingly 100% of the time when driving a flat country road, phasing in and out with throttle application. At 40, I can shift to 3rd, and no issues (higher RPM). If I drop to 30mph, it starts all over BUT it's much harder to keep a steady throttle foot at that speed/rpm and the vibe duration is much shorter. In 4th, it just seems like a natural place for it and we buzz along down the road.

 

Holy Crap .
Thats some nasty vibrations !!!!
Pretty much the worst I have seen on Tacoma World .
We gotta get your truck on a scanner and look at some live data as well as codes
I would like to see when the torque converter is commanded on as there are relay valves available in the aftermarket that repair a worn valve body for issues like this . Very interested to know what the bottom of your transmission pan looked like when you changed the transmission fluid ?
Pressures would have to be measured and the valve body will have to be dropped
https://www.sonnax.com/parts/2764-zip-kit

One thing you should try is loading up the transmission in drive . This is better known as a stall test .
Hold the brakes hard and slowly increase the gas pedal to match the engine rpm where you get the vibration as if you were travelling down the road (12-1600 rpm ) .
Allow the transmission to cool in park with the engine running after the stall test has been completed .
If the truck starts shaking and fluttering with the brakes held hard during the stall test , similar to what you feel when the fluttering occurs when you are on the road at the same engine rpm , we can eliminate the torque converter .
Your video was a good representation of the issue . It put me back to a torque converter problem immediately . Not a normal shudder but an incredibly violent shudder to the point where I think we are steering towards an electrical solenoid issue.
Not something Tacoma World sees on a day to day basis . This I promise you