Cannot Fix Vibration/Bounce - Dealer Throwing Parts At It

What's up y'all. I normally lurk on forums and find solutions when I need one but this time I cannot find a single person with the same experience. Maybe I'm special.

I purchased a 2016 TRD OR package truck with 88k on the clock. Ran and drove fantastic until about a few days ago.

I started to notice driveline vibrations when decelerating from 30-10, found the TSB for this and my 2016 OR is in the vin rage affected by the pinion flange angle. Outside of the TSB coverage for this to be free, I could care less about a tiny vibration.

Few days ago the truck began bouncing and shaking when accelerating lightly between 18-27mph. The truck visibly bounces and shakes then smooths out with no issues at any speed. Slowing down through this rage does not affect it either, only when accelerating. If you press the pedal more than an average amount, nothing happens as if the issue doesn't exist. Flooring it is the same way. This happens in 2WD and 4Hi, with and without traction control.

I got tired of it and took the truck to my local Toyota, they wanted to do the transmission software update. Still didn't fix it, exactly like I told them it wouldn't no other symptoms with trans. They are denying it's u-joints or center bearing, but adamant of performing the driveline vibration TSB. I'm out of warranty for the TSB so this will run me a cool $1350 plus tax. The springs aren't broken, and I've had the driveline vibration since purchasing the truck. I'm just not too keen on paying dealer service prices to throw parts at the thing. For $200 I can get the updated springs off a 2017+ and do it myself.

Its a coincidence this started happening shortly after getting my exhaust swapped with the MBRP and subsequently changed to a flowmaster. But exhaust is not going to make the truck bounce like that.

Does anyone have an idea as to what I should try next before paying the dealer to guess at it?

I will be greasing the u-joints tonight and check for any play in the driveshaft.

 

Try it in S3...symptoms still there?
Ever serviced your ATF?

 

There was a prominent member who had a similar issue and found u-joint need bearings grinded to dust.

 

S3 makes a slight shudder at 17-20mph
And very light at 24-29mph

Higher speed shudder significantly less than S4 or D due to higher RPM.

they performed the trans software update today, what’s your thinking? Mechanical in trans?

 

Honestly wouldn’t put it pas this being a possibility. Before removing the driveshaft and checking the joints, you think pumping them full of new grease would lessen the issue (if it’s still present but less noticeable then possible bad needles?)

 

Check for some play. Replacing seems not that hard

 

Torque converter clutch partial application; Toyota calls it flex lockup.
Could be the torque clutch, clutch solenoid, master pressure solenoid or related valve body fluid circuits.

The sudden onset has me thinking this, rather than a driveshaft problem.

 

No play at all. Just went and ran new grease through them. Rears took 12-15 pumps to purge fronts 8-9... Im going to assume the prev owner didn’t care to do them and the toyota he took it too were negligent.

I’ll see if that does anything then look into possible replacement. I’ll remove shaft this weekend and drive in 4Hi

 

Yea I thought it was trans related too. But it wasn’t too sudden. You’d notice it a little a week or two ago. Drove through plenty snow days since.

dealer can’t look at it again until Wednesday so I’ll definitely have them check the trans itself. Until then, u joint testing might be the only option I have in the garage here

 

Well...
- it happens on acceleration and deceleration in the speed/load ranges flex lock is applied in S4-D
-symptoms are reduced when flex lock is canceled or at least reduced in S3

Unless your u-joints are totally ragged out, it's gonna require removing the driveshaft to check for slop.
I don't think you'd have those symptoms without ragged out u-joints.

Is it stock suspension?

Another thing you can check in the interim, is your u-bolts(52 ft-lbs). I doubt that's it, but worth a try.

Definitely keep an open mind...
I'm just some dude on the internet.

 

I’ll give the u bolts a check this weekend as well. Yea regreasing the u joints didn’t do anything.

Would low trans fluid be a culprit?

Yea but internet people usually have a more open mind than the dealer. They’re 100% insistent that they replace the leaf springs and charge the 4hr labor before trying something else...

 

Gopro with magnet or duct tape?

 

Update:

Did more testing since the vibration and shudder only occurs at specific speeds. U Joints were greased last night and not broken, issues with these would have showed symptoms at all speeds. U Bolts on the rear springs would have caused excessive bouncing over bumps and/or all acceleration times. 100% pointing to transmission issues as suggested above.

Looking at the charts for when the torque converter locks on our trucks and our cousin 4Runners, it happens exactly around the gear change from 3-4. At low rpm acceleration the transmission seems to shudder because it is not recieving enough pressure to make the shift smoothly. An extra test for anyone else having the issue to do is place the truck into ECT power. It lessened the issue and needed VERY little throttle to make it happen, this could be that the pedal position is being interpreted by the trans computer rather than traditional hydraulic shift points.

Side note: when the truck is cold and trans has not reached operating temps, the shudder will not occur no matter how hard you try. Most likely because the cold fluid has a higher viscosity which allows for the solenoids and torque converter to engage at proper intervals.

Knowing this I decided to dive into the maintenance schedules. With my previous work truck Tacoma, we abused the hell out of them and every 60k the transmission fluid was replaced under the service interval. Yet Toyota, and their infinite wisdom, seem to believe that only towing applications and off road heavy rigs should have the swap. The rest of the world only needs to have the pan checked for leaks... You can't tell me that in the 90k miles on my truck the ATF is still pristine while someone towing or on dusty roads will have had the fluid swapped 1.5 times at the same mileage (obviously the next service is 120k for them).

CHANGE THE DAMN ATF!

Towing package trucks need just under 11 quarts of ATF and non towing packages need just under over 10 quarts. At autozone I could get the fluid needed for $150 and begin the long process in the garage.

I took the truck to a Valvoline (yes the instant oil change place). They do full trans fluid flushes for $149 on the Tacoma. 45min later they pushed out 10.9 quarts of dark fluid and put in new bright shiny red liquid.

Driving away from the shop it still had a shudder. Few miles down the road the shudder was less pronounced. 30min of driving later and it is non existent. I have yet to replicate the issue. I'll keep tabs on the issue over the next few days and let y'all know if it comes back.

 

Thanks for the note.

Winner winner chicken dinner.



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