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8 speed transmission issues

32K views 93 replies 15 participants last post by  captainm27 
#1 ·
I have a 2017 Toyota Sienna LE with the 6 cylinder 8 speed drive train. We are constantly getting a bump shift now and it is getting more constant when cold.
It happens when you first start off in the morning and when you come to a rolling stop, Another words your slowing down for a red light, the light turns green so you go to accelerate and wham .. it hits that shift hard and lurches forward. Just wondering what this could be. I am out of warentee by years (only 21K on the van). Is this software related?

Also is this normal behavior for this transmission? The last real stepped auto that I have had was back in 2005 (been purchasing hybrids since them or compact cars with CVT) and I never remember it acting like this
 
#2 ·
Call Toyota Customer Care and open a case. There were several TSB's issued over a 2 year period for software updates and a set of VIN numbers (traceable to transmission builds that were truly bad) that qualify for replacement. There was a quiet extension of the warranty depending on the circumstances and severity of the issue. So while you are outside of the basic warranty, you probably still qualify for the powertrain (5 year / 60k miles) warranty and possibly even one of these extensions.

Do a search on the 'General' and the 'Problems' section of the Gen-III segment for links to some of the documents and details.
 
#3 ·
Fibber thank you for your response. I will do that. I never got any other notice from Toyota so that is why I am concerned. I am wondering if the other crossovers with this combo are having issues also

I am kicking myself in the ass for not getting the 2016 with the older combo
 
#4 ·
TSB's are notifications to the dealership shop that there is a known problem, and how to proceed with a repair. They aren't supposed to be seen by the likes of us (customers), but we have our ways! If you complain, they will act. If you keep quiet, they remain stone faced dumb on the issues.
 
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#5 ·
yeah it looks like I am going to have to raise holy hell in the dealer to get this thing fixed or I think I am going to trade it in .. I have not decided yet at this point.
I also see that the highlander uses the same power train. i wonder if this is across the board,
 
#6 · (Edited)
I cross-posted some of the TSB's over on the ToyotaNation Highlander board, as the vehicles share much of the drivetrain. They were clobbered by it too (2017-2018).
 
#8 ·
I have a 2017 Toyota Sienna LE with the 6 cylinder 8 speed drive train. We are constantly getting a bump shift now and it is getting more constant when cold.
It happens when you first start off in the morning and when you come to a rolling stop, Another words your slowing down for a red light, the light turns green so you go to accelerate and wham .. it hits that shift hard and lurches forward. Just wondering what this could be. I am out of warentee by years (only 21K on the van). Is this software related?

Also is this normal behavior for this transmission? The last real stepped auto that I have had was back in 2005 (been purchasing hybrids since them or compact cars with CVT) and I never remember it acting like this
We have a 2018 LE with an 8-speed transmission.
I remember that the dealership did some ECU firmware update during one of the services and the shifting seems to have become a lot smoother. Maybe I'm just imagining it. We have only 10k miles on the van.
 
#10 ·
Yeah we are making an appointment to get it looked at along with the annual New York State inspection process. There are really no other options out there from Toyota that are in our price range and we love the versatility of the mini van. Having a somewhat large family along with our elderly parents just enforces the need for the 7 to 8 seat Van/suv. Since the highlander uses this same transmission it would be a no go for us.

I would love to actually get some of the safety features also but I am not willing to pay almost 40k for it.
 
#12 ·
I have called around my area to three different transmission shops. One flat out told me to take it to the dealer as they don’t service these transmissions due to the complexity of filling it up. One told me to bring it by And he will see if it is an electric issue. The third shop said I probably will need a new one and it’s close to 9000 to replace.
At this point I am taking it to the second shop next week to get a diagnosis along with some WS fluid as they also said it could be low
 
#17 ·
I may have to consolidate and repost some of the old info on UA80 8spd tranny issues for 2017/2018. If you follow some of the links mentioned above, you'll find several pointers.

Here's one:


Basic coverage is 5 yr / 60k miles. If you call Toyota and open a case, they will often extend coverage beyond this as there was so much bad press on these early transmissions.
 
#18 ·
I definitely will open up a case with Toyota on this one. It happened to us again.. sluggish off the line, funny shifting when cold.
my father and I took it for a quick toot for a couple of miles just now. I hooked up an Autel and monitored the trans temp. when we are done it was at 199.98 degrees F. It will go in this coming weekend and if we are not satisfied with the outcome my wife and I will raise hell with Toyota. It’s just not right with this god awful UA80. We shall see what happens.
 
#22 ·
That was the same for me. I'll be honest, the new transmission shifts much better, but there's no escaping it, it still doesn't feel as powerful as it should. Part of me wishes I had purchased a 2016, as that was the last year with the 6 speed, which, although I have not tested, folks do say feels much peppier.
 
#23 ·
we had a Camry with the 6 cylinder and 6 speed. That thing use to fly when I would put the pedal down . Before anyone says anything ..yes I know there is ia weight difference.. but I dont expect it to be this drastic. We test drove the 2016 and the 2017 but were talked into purchasing the 2017 for better fuel economy.. I think we made a bad decision. This one is an LE as we did not think we needed much more then that.

it is good to know that it shifts better and I hope we will have the same outcome. I have to tell you though, if we are still not happy we might just ride it out till the power train warentee is over in 2 years and start looking to the gen 4
 
#24 ·
I can't comment on the MPG difference, as this is the first Sienna I have ever owned. But, I would gladly take 1MPG less for better performance. Having said that, I did manage to get 30MPG once on this van.

 
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