Dealer says the solution to my stuttering at low rpm accel is a new tranny... Really? Need guidance

Another tranny issue

 

We don't have access to PWM, duty cycles and line pressures at the moment. Supposedly all these are coming
BTW, toyotas TCU data list doesn't not have line pressure, duty cycle etc.
So we have to use what we have available and adapt.

 

https://wynnsusa.com/product/transmission/shudderguard/ I had a shudder problem in my 2015. Local independent garage recommended this product from Wynns. After 1000 miles of driving it has pretty much eliminated my shudder problems. I have an extended warranty but they would not cover a new transmission for what they indicated was a common problem. I also have a friend who had the same problem in a late model Dodge van. So not just a Toyota problem. Hope this is helpful.

 

We are supposed to be changing fluid every 30k!?

 

Are we sure it’s even transmission shudder at this point? If premium gas helps or eliminates the problem wouldn’t that point back to engine tuning? The shudder is felt when the TC is locked because it’s a solid connection to the engine at that time.

 

We? No...

 

I was going to do mine at 60k. I had no idea there were people doing it every 30k.

 

I do a full replacements at 30,000.
Some do a drain and fill only every 30,000 miles.
I'm currently at 41,000.
Those are the 2 scenarios I covered in my post and am comfortable with.
There is documentation to support anything from 2yr/12,500 miles to never.
Do what you are comfortable with...

 

I really should do that. Between my tire size and driving style 30k changes would be a good idea. Just haven’t done one yet (first auto) so I’m a little hesitant. Haha

 

It's not too difficult...
I follow the service manual method. It's basically doing the drain and fill three times, cycling through the gears between each and ending with the temp check fluid level adjustment. The fluid is surprisingly clean all said and done.

Some opt to exchange through the cooler lines, but I have my reservations about that method.

Some opt to drop the pan and change the filter; I didn't. Maybe at 60,000...

 

Thanks. I’m at 50k with a big trip coming up with a long list of stuff to get done before that. If I have time I’m going to do your method. Either way it’s going on my short list to get done. Depending on how dirty the oil is I’ll think about doing the filter too.

I haven’t done either but it seems like drain and fill 3x can’t really be much more work than the filter swap.

 

every 60k. i do a drain and fill every 15k. I rather have fresh fluid than debate the "lifetime" fill perspective. it's not hard to do, just time consuming.

https://empyreoffroad.com/blogs/res...toyota-tacoma-diy-maintenance-reference-guide

 

UPDATE...

Went for a 2nd opinion today to a transmission specialist... Short story, complete refill of ATF, new filter, add anti-shudder additive, drive 300 miles, get back in touch if there if the shudder doesn't go away.

Long story...

Described problem to lead mechanic; told that the correct transmission term for the issue is "shudder." Left the truck with the mechanic. Two hours later, test drive presented a slight shudder (of course not as much as previous days), diagnostics completed (no issues), pan was dropped, oil inspected, magnets checked. Magnets showed a very slight amount of metal, likely from the bearings. Oil was definitely aged. Appears the dealer I went to for maintenance in the past (not the new transmission guys) may have done a fluid change or at least filled the transmission. Will be looking back through old paperwork to see.

The issue with my truck... varnish build up likely on the TC clutch(s) - thus, the anti-shudder additive used to break up the varnish and renew the clutches.

Lead mechanic says he sees the shudder all too often now in these modern 6+ speed transmissions, and a bit higher rate in Tacomas. The issue... The service schedule says replace ATF if towing, car top carrier or heavy vehicle operation. The dealer (at least the one I went to until 75k) throws at you a bunch of 60k optional services and says it's for the heavy uses of the truck. Tells you they aren't really needed if you are driving the truck on the street mostly. NONSENSE. This is horrible advice according to what I found out today. 50k is suggested by the transmission shop regardless of use type. Funny thing, according to Toyota, they still claim the ATF is life long for normal use (SOURCE: https://www.toyota.com/owners/parts-service/maintenance-schedule, check 60k and 120k). I should have never trusted the dealer or Toyota. The lead mechanic mentioned a lot of manufacturers are playing this game now with "life long" ATF. His Jeep SRT has a BMW transmission in it (used in 7 Series cars). Supposed to go 120k without service. Nonsense. He serviced it at 80k after feeling some shudder and found the filter complete gummed up. His advice, 50k for normal driving, 30k for heavy use driving. The concept of life long ATF was asked at a ATRA seminar that we went to last year. The Lubegard engineer there says it's complete nonsense of life long ATF. The manufacturers are simply trying to get your vehicle out of warranty, knowing that it's likely to be scrapped or sold. And statistically, the occurrence would still be low enough of out right transmission failure. Besides the Lubegard guy said the filter won't last!

Morale of the story:
1. 30k/50k ATF changes depending on use case... the same for diffs and transfer case. I have more service to schedule!
2. The dealer techs are generalists. They are told there is an issue with the transmission based on their diagnostic computer. Solution replace the whole thing regardless of cost.
3. Always get a second opinion if the cost is high.
4. Don't trust the manufacturer.
5. Don't trust the dealer.
6. And, send big thanks to the folks at your favorite auto forum for the advice and guidance!

Hoping not repost in 300 miles...

 

Glad you fingered it out, amigo! Im at 41k as my daily (80mph on the freeways in SoCal) driver. Will be finding a reliable local guy.

 

I can't find fault in anything you posted.

My $.02, fwiw.
Use S-mode and ECT... Use only a high a gear as you need; S4 around town, S5 on the highway...lower if you can. IMO, it's the flex lockup that burns up the TC clutch. Flex lockup is supposed to extend mpg and smooth shifts; that's a lot of slipping and engaging. This strategy limits the time spent in flex lockup.

 

The lead mechanic shared some thoughts about modern transmissions that you may find interesting @splitbolt . They don't always make sense! They actually "learn" your driving style and "optimize." His Jeep is a great example. His wife drove it for about 200 miles. He got it back, and it was like a different car. He told his wife that if she ever drives it again, she can't drive like a granny! For Tacomas, he says they shift a bit odd at times. People attuned to this oddness complain, rightfully so. And, the best choice is to get a tune to firm up the behavior and prevent it from changing. Not sure if the lost optimization or whatever that may mean in Toyota's software means to the overall scheme of things.

Interesting you say flex lockup extend mpg... My impression driving home today was that "optimization" is likely only done to get better EPA fuel economy numbers while testing on their "standard" driving conditions. I doubt it has anything to do with function, life, etc. My thoughts, no data... but...

 

D(AI-shift) is the learning mode...economy mode...whatever.
It's convoluted, to say the least; and poorly executed. OVTune use to have a blog page called, "this is why you hate the AC60 transmission"; he wiped it from his website. He is persona non grata here, now.

When you try to please everyone, you please no one.
Yeah; I, like you, suspect it was also set-up to game the test.
Until someone can monitor and tweak flex lock-up...it's one reason I've obstained from a tune.

S-mode/ETC limits the maps it can pull from.
Try to keep the RPMs to at least 1,800-2,000 when cruising. You might think it's less economical; IME, it's really not. It spends more time in full lockup...

 

This guy has over 300k miles, and he changes transmission fluid every 50k. He also suggests changing the rear diff fluid at 10k to start because the OEM fluid looked like crap.

 

Mines a 2017 180+ miles dd road trips I'm doing my 4th transmission service next week at the dealer . I hope you get this resolved sorry bud

 

I maintain transfer case and rear end every 30k . One time I let the rear diff go to 50k interval. No bueno. Front diff 50k . I off road but not long extended times . I went to moon rocks and funny rock in the summerlast year here in Washington state and elk camp last season during the fall . Bout the most I use 4wd . But transfer case and rear end yeah 3k to 4k mi a month . Man I drive a lot .