Hey guys.

2017 ES350, 80k mi. I DID do a drain & fill a while ago.

I'm running into this new issue that I just noticed maybe a week or two ago.

When I'm coasting on the highway at about 60-70 mph (foot off the gas) and I press down to accelerate (heavy, light), there's like a veeeeery slight shudder? jerk? hitch? It's like maybe a quarter of a second, but I feel it when I press on the gas, before the car responds.
It's not downshifting thats the issue.
I mentioned this issue to one of my friends and he stated that it sounds like the torque converter is acting weird and that I should reset the transmission programming. I'm planning to do that this weekend, but I'm unsure if there could be any other issues potentially happening.

Is anyone else running into this? Is this normal? I feel like I always hyperfocus on something that I think is an issue, so I'm not sure if this is just normal behavior for the U660E.

 

If it's not a programming issue, maybe you could use this:

Lubegard 19610 Instant Shudder Fix

Lubegard on Amazon, $8 USD

Lubegard on Amazon, $8 USD

I've used it in a couple of cars/trucks over the years, including my .04 Chevy 2500HD, a week ago, just before getting it inspected (it had sat unused for upwards of six months, so there were items I needed to address), and other guys I raced with used it too, in both their drag cars and tow vehicles. Its only a 3 ounce tube, so you don't even need to take any fluid out, just put this in. Can't hurt.

 

Hard to say. It could be the transmission having a symptom, or it may be your motor mounts, or suspension.
If you did incorrect fluid replacement procedure (without temperature monitoring to refill), or used anything other than Toyota/Aisin WS fluid, your symptoms could be related.

All in all, it's almost impossible to diagnose over the computer. If this bothers you, you have to take it to a competent mechanic that can start ruling out the systems and narrowing the issue down to the actual cause.

How many miles since fluid replacement? Does the symptom happen both when hot and cold? Does it matter if you are going uphill or downhill? Have you checked the motor mounts? What's the transmission's service history? All of this matters.

 

It's about 10000 mile since the drain and fill. I used Aisin WS fluid and followed the leveling process with temperature monitoring done thru TechStream. Other than the drain and fill I did, I'm unsure of the service history (2nd owner). Filter has never been changed as far as I know.
Uphill/downhill doesn't seem to matter. It happens at about 40 / 70 mph increments and it's seemingly at random. Whether I press lightly on the pedal or harder. I think what I may be feeling, is the torque converter locking/unlocking, but I don't recall ever feeling it like this.
I haven't checked the motor mounts or the transmission mounts, I will when I do my oil change this weekend.

 

if you are worried about torque converter shudder, coast the car at 30-45mph and then apply slight throttle. you should feel the tc lock and unlock randomly. if no shudder then torque converter is good and your shift logic may be off. put the trans into S mode and go through S4-6 to replicate your problem. If no problem with S mode, then its for sure TCM shift logic in regular drive. If you do notice it in S mode but without the shuddering at 30-45, i would look at mounts or throttle body. If you notice shuddering, you need a new tc (Hopefully not the case).

 

It may be the solenoids inside your transmission. I had to get new ones installed in 2009 in my '04 Chevy 2500HD (with the 4L80E transmission), because it was doing a shudder/stutter at certain speeds in stop & go freeway traffic. It didn't affect it in regular operation, nor when towing my trailer. Since the repair, it hasn't done that again.

However, it has recently (in 2024 and now) started to shudder/stutter sometimes, when leaving my yard's parking area (uphill, on loose sand & gravel), and I've been using the "Tow-Haul Mode" in first gear, to prevent that from happening. This was the vehicle I just put the Lubegard additive into, and after a few days, I no longer have to use the "Tow-Haul Mode".

 

So I just tried this, and yes, what I believe i'm feeling is the torque converter locking/unlocking. Shudder claims was definitely an overreaction on my end.
I'll take a look at the mounts this weekend and also a look at the throttle body, hopefully I'll find something there.

 

I think I'll try the additive as a last fix, I'm going to check the mounts first and see if I may just be feeling the torque converter locking/unlocking. I haven't heard of many solenoid failures on the Trans for these cars, so I'm hoping its not that.

 

It never hurts to change the front and top mount as they see most of the torque strain. I changed both of mine at around 90k and it really smoothed out the vibration at idle in gear.

IMHO if you are feeling a vibration in the torque converter lock-up, mounts will only hide it not fix it.

If you already know how to do a drain/fill, do yourself a favor and drop the pan, clean the pan and magnets, change the filter and fill (pan drop and filter will take about 3 to 3.5 quarts). There is one bolt that is very hard to get to on the pan (frame is in the way), I used a modified 10mm wrench and turned it 1/8 turn at a time. Replaced it with a torque bit when installing the pan. I also did not remove the cover underneath, I just cut it away neatly (using a sharp box cutter) to gain access as I have already done a pan drop and filter change twice. Mine is at 105k now and runs/shifts better than new. You can also add either lubegard or BG transmission additive. I have used both and they work extremely well.




https://www.walmart.com/ip/BG-ATC-PL...erId=101004802