Transaxle Failure: no ICE, no codes, no go.

Thanks for the pictures and the details.

 

First of all, ouch!
Second of all, the owner was fortunate to have someone like you that knows what he's doing, working on their vehicle.
But really, you had me at "the ICE turned with the wheels" I thought I was going to have to back and study the power train again. The ICE doesn't turn the wheels. At least, not without the MG's pushing back. So, yeah, that was wrong. And my understanding is safe, at least for the foreseeable future.

 

Thanks for the post and analysis!

This is a little worrisome. This isn't the first post of some expensive Prius part failing due to assembly error. Once the transaxle is fully assembled and if it passes functional tests, this seems like it's not anything Toyota would catch at the final assembly stage unless some test fails at that point.

They might catch it by taking apart a random sampling of incoming parts.... Hope this assembly error is very rare.

I wonder if there's any way to detect this problem earlier. Maybe UOA of PSD fluid or by looking at how much crud has accumulate on the magnet at each PSD fluid change? Thing is, none of us do it that often and many of us (including me) don't DIY.

 

I'm sure by Toyota standards there's no assembly defect of any significance here... I mean the transmission went out at 140K. Isn't that an acceptable level of durability by their standards? I mean how could this car have gotten that many miles with an assembly defect as severe as described?

Regardless, this is for sure the dark side of Prius love that we'd all like to avoid. I mean you can do everything right with care and maintenance and sometimes that's not enough. What's worse good online community-connected mechanics of due diligence like Seilerts are hard to find!

 

oh HELL NO!!!

might be to their standards but not to mine

 

Yes on both counts. I'm the unfortunate/fortunate owner. Having the transaxle fail at 140k miles was definitely a bummer, but I was very glad to have someone as knowledgeable as Seilerts working on my car (especially since I was going out-of-town the morning after the failure).

It's also nice to know the underlying cause of the failure. As Seilerts stated, I had the fluid changed at 60k and 120k miles. Unfortunately, I was lazy and had the dealership do the changes, so I don't know if there was much accumulation of wear metal on the magnet at those times. There apparently wasn't enough for them to mention it to me, at any rate. I did look at the fluid from the first change, and it seemed to be in reasonable condition. My wife took the car in for the 120k change, so I don't know what that fluid looked like.

Very interesting to see the photos! Since I was away, I didn't get to see the transaxle in person.

As cwerdna said, hopefully this is a very rare assembly error.

 

the fact that it was an assembly error means being "out of warranty" does NOT apply here!!

do we limit recalls to "cars under warranty?" i would get with Seilfert and document what you have there and present to Toyota corporate. there is no time limit in my mind on mistakes done at the factory

 

As much as I'd like to agree with you, Dave, I don't think Toyota would be amenable to covering something that failed so far out of warranty, assembly error or not. Since it was a mechanical failure, this would likely fall under the powertrain components, thus it's more than 100k miles beyond the warranty period. While the failure may have been premature in that we consumers hope these transaxles will normally last much longer than 142k miles, from Toyota's perspective it delivered good service for a long period despite the assembly error.

 

"amenable?" oh definitely not, they would be anything but happy or open to admit error here

but responsibility and integrity also play a part. once again, there is no mileage or time restraints on recalls so why should this be any different? it was a mistake made by Toyota at the factory.

now, can it be proven? maybe not now. tearing it apart may have eliminated that possibility. but just saying ya know

 

Ahem!

Another diagnostic technique is sound analysis. I have no doubt that a spectral analysis of the transmission noise could have detected the early symptoms. But a diagnosis is not a fix and by the time ordinary detection systems had found there was a problem, the only option remaining would have been to schedule the repair.

Bob Wilson

 

I just clipped this out of a random search, but it's familiar to fine-print readers across the land:

This pretty much puts a time limit on long a manufacturer has to back their product. After that, it comes down to basic decency and how they want to appear to the interested consumers. Dave and I are familiar with the treatment our favorite all-electric car is getting from its manufacturer (that being dead silence) as its batteries start to sag in the hotter climates.

 

A mandatory recall typically addresses a serious safety issue. A transaxle failure usually would not result in a safety issue. The number of reported 2G transaxle failures has been quite low considering the vehicle population, so I doubt there is a systemic problem.

 

i seem to remember several recalls that did not have to do with safety, only premature failure of a component. but my memory is not the greatest so i will have to get back with you on that

 

That's good that the transaxle failure is low among Generation 2 Prii. How common do you think it is? I found a Web site called Luscious garage that said that Generation 2 transaxle failures tend to happen between 150K-250K, although I have read on the 299,999+ mile club that a lot of those people had not experienced transaxle failures. How likely are any to fail before 100K miles?

 

Not very likely, although a very small number of incidents have been posted here. I think the Luscious Garage assessment is reasonable. Certainly some transaxles might last longer, while others will fail sooner.

 

Thanks for the info. Currently trying to figure out if the transaxle might be having issues (I think MG2, whichever the gasoline engine part of the transaxle is). Two separate times some shaking while in park when ICE on (won't stop until electric only kicks in). Also, the car jolts when ICE is on and moving into park, sometimes into drive. Also, occasional issues with acceleration (although only happened twice).

Thanks again for the info. Had my transaxle fluid changed at 65,600 miles or so.

 

The engine can cause this kind of motion, "jolts." As a suggestion,

• check throttle body plate
• check sparkplugs (and the wells, I remember something about water getting in igniter area)

I can reproduce roughness in our NHW11 by letting the car coast in "N" on a flat access road starting above 42 mph. At 42 mph, I quickly shift into "D" and back to "N" about a second so the engine stop logic does not have enough time. I can feel and hear the engine 'rough stop.'

GOOD LUCK!
Bob Wilson

 

There's no guarantee that the LG assessment is based on a representative sample. If they tend to see PSD failures at ~150k-250k miles in the vehicles they maintain from day one, and there's no bias in those failures due to the vehicle being operated predominantly in or outside of the city, then there might be something said for their assessment, but w/o controlling for both of those potentially confounding factors I'd take anything from them with a grain of salt. If anything my guess is that there are some failures due to incorrect assembly/poor components/abnormal use and wear that tend to manifest at around 150k to 250k miles, but an average lifespan of ~200k miles for something as mechanically robust as a PSD is incredibly short.

 

As a point of reference, the Luscious Garage post is found here: Luscious Garage | Blog | Gen 2 Prius (2004-2009) Transmission Failure, P0AA6, P0A92, P0A7A

In the article (in the 3rd full paragraph) it talks about their experience with Generation 2 Prius taxi cabs. That may very well have a bias.