Jerks at 45-50 mph, transmission suspected

Unless you have tons of mileage on it, should still be under warranty.

Mine did this, granted I have a 17. Dealer applied a tsb update and it fixed the issue. This was in 2018. I'd be a little surprised if they didn't roll the newer models out with the new software.

 

Both are correct. I had shudder really bad on my 17. The issue is the truck can learn to hold 6th way too long when it really needs to downshift, which causes the big/jerk/shudder. Unfortunately this sucks, but is “normal” for the truck to do.

My 23 drives like a dream right now. No issues it all. We’ll see how long that lasts, but if I didn’t know any better I’d come into the thread being like wtf y’all talking about?

 

Curious how many miles on your truck? I have 3800 and its a jerky mess.

 

Or...the way some folks operate their vehicle, avoids those conditions.

 

My brand new 2023 SR5 with 1,000 miles has the shudder.

To replicate, bring the speed to 45 mph. Stay as close to 45 mph without allowing the engine to rev up / shift to a lower gear. As the engine "bogs down" the truck will start to jerk. You can feel the jerk in the gas pedal and the seat. It's easiest to replicate when going up an incline. It happens through normal driving every time I drive the truck through town.

Someone on this tread mentioned T-SB-0058-18, but a google search shows that is for a 2016-2017 model. Anyone know of a TSB for a 2023? I'd like as much info as possible when I take it to the dealership. Any info anybody can provide is much appreciated.

 

About 100.

 

What y’all are experiencing is inherent to the trans logic. In the past, TC’s were either locked or unlocked. Toyota, in their infinite wisdom, uses another state: slip-lock. Those two words don’t belong together. The only thing you can do is lean into the pedal to unlock the TC, shift to S4, or tune it.

 

My '23 would shudder in 6th under load. Thought it was spark knock. I checked it myself, and it was exactly 1.4 quarts low on transmission fluid! The shudder is gone now. Drove 5,800 miles before bothering to check the fluid 'for fun'.

Make sure you check your transmission fluid. I don't care that they are sealed. You have to check it. Mine is a case of low ATF from the factory.

 

Its a software issue, not the fluid level issue.

 

Mine shudders. Checked the fluid according to the prescribed method within the last year. It was within 1/4 quart. Still shudders. 20,000 miles.
Not saying that it's not worth checking, but it's definitely not a cure all.

 

The weight of the truck and the slight incline in 6th gear is overwhelming the torque of the motor. Figure out the amount of torque the engine makes at 1200 rpm add in parasitic loss for drivetrain ie transmission, front rear diff, etc, and you will find the number to be quite unsubstantial. Now add in the amount of force required to move the weight of your vehicle on a flat surface. Then add in the physical adversity of the incline which is adding fighting gravity into the situation.

If the engine doesn’t downshift the strain has to be sent somewhere. Torque converter is the first piece of the driveline that’s accepts it. Not enough fluid pressure on the vanes to keep it symbiotic and it starts to shudder/slip in the lack of pressure to keep it moving against everything mentioned before. That strain will always be there. Easy fix is to downshift to allow the lower gearing/ higher rpm more torque to overcome the torque strain/insufficiency.

Now add in the lunacy of a computer controlling the shift points instead of fluid pressure and you have them both working against each other. The torque converter is screaming for more pressure to stay moving against all the forces (which needs more rpm/more torque which is accomplished by downshifting in our engine) and the computer is saying hell no we need mpg not efficiency and I’m not shifting so you’re not getting the extra pressure you need.

Higher horsepower cars have this strain but on the other side of the spectrum. Their excess torque also taxes the drivetrain in the same way but with an excess not insufficient.

Couple this with the fact that our engines make torque in the higher end of the rpm scale it should not be a question as to why this is happening. You need more torque which means more rpms. Hope this helps explain it.

 

So, did you take it to the dealer, what did they say or do? My 2023 with 3500 miles jerks at any speed when it's in 6th gear.

 

I have not carried it back to the dealer. Sounds like it's a common issue and I haven't seen a thread yet where anyone has found a resolution.

I'll ask about it at the 5k mile oil change.

 

Hi all. My wife just bought a 2023 4runner and I bought a 2022 Tacoma. I love her 4runner so much (not ONE bad thing to say!) that I kinda overlooked a good test drive of the Tacoma. My mistake.

The 4runner is amazing but the Tacoma only has 9600 miles on it and sounds (not during my short neighborhood test drive though) and shifts like crap. My search brought me to this thread. I planned on joining anyway of course but not this quickly. I am in the 4runner forum as well.

Thanks for the thread and the responses here all! It cleared some things up for sure.

I am pretty mechanical, so I fully understand ya'll's comments, but did not anticipate not liking this thing. As soon as I bought it and actually put 100 miles on it outside of the neighborhood I realized this.

I got a decent deal on it so I don't think I'll take a hit but man what a disappointment.

Guess I gotta decide!

Excellent post @PTSDTherapy

 

My exact thoughts after owning this thing for 5 days and reading all of this.

 

My 2023 doesn’t do this at all. Shifts perfectly and no lugging

 

The best solution is to tune it. No amount of ECU learning can overcome the crap logic. It’s a night and day difference.

 

I tried replicating this on my ‘23 OR and it just won’t do what others are saying. It bogs down, but just stays rock solid. Hopefully a tune can fix it for those who need it. I plan on doing a tune after the first oil change.

 

Need to have a few parameters to line up:
Specific speed range, low rpms, high engine load, 5th gear, torque converter in a fully locked state and the traffic.

 

OK. I've got some reading to do!