Transaxle Failure

Is there a way to preserve the transaxle life other than replacing the fluid?

 

Nope thats your best bet but also take it easy on big mountains with big weight load. That and a low hybrid battery charge will cook the trans.

 

How does a low HV battery cook a trans?

My HV battery state of charge (SOC) is often quite low while climbing larger hills or mountains (this vehicle already has a new trans, and isn't looking for another)

 

Because the battery/engine tends to not be able to provide sufficient voltage & current under such extreme loads the trans motors are demanding especially at low soc on a big hill climb at speed.
High power because you are demanding it via the gas pedal. Under load lower the voltage the higher the current. The motor winding's take the brunt.

Many posts here over the years about people on the side of the road with an overheated Inverter attempting to drive up a big mountain with low soc and maintain speed and power all the way up. Battery soc getting very low, power output of engine at max and engine screaming, speed falling off so you floor it to maintain speed.

The perfect storm is a heavily loaded car, steep mountain, and very hot day, and trying to go fast. Seen that many times here. They always report engine was screaming and burning smell. Did they pull over...nope. The best way to blow out motor winding's. Run an electric motor so hard it almost stalls and the current draw goes off the chart. These are the same dopes who have never changed there Inverter coolant or there trans fluid.

Next time you go up a huge mountain with low soc maintain the speed and do a before and after inverter coolant check. Use an IR thermometer. Do it on a hot day. You may not even need a IR just open the hood and smell. You'll know its in trouble when you hear the engine screaming.

In all cases if the engine in a g2 is screaming under load that means there is very low hybrid battery output or the load has demanded way more current than the hybrid battery can contribute. Hilarity will ensue. Its the Achilles heal of this under powered little car and should be understood.

If you consistently drive hard enough that the engine is screaming all the time make sure you have good Inverter coolant and good trans fluid because your demanding alot out of the car.

In the G3 they realized the under power of the G2 and have more powerful and efficient mg's. Better Inverter cooling and a better planetary gear setup eliminating the chain etc. Big difference in power between the G2 and the G3. G3 can handle hills and instantaneous high loads much better.

 

Thank you for allowing all of us to tag along from the beginning of this process.

When you post photos, please try to provide a log in which you describe what each photo represents.

 

I have a 2007 prius touring 170k i just learned my transaxle is failed. code PA006, looking at many other chats i originally thought inverter pump. No sounds or noises gave foresight that this would happen. While leaving work Red warning light, VSC as well as red exclamation mark on car displayed. I drove vehicle home turned off did not turn over ready untill next day. i found a transaxle that fits for $235 just struggling to find mechanic to do labor any one have any ideas?

 

You were not the original owner?

 

That does not seem to be a valid Gen 2 code. Perhaps you meant P0A60?

If it is, there are 6 sub-codes associated with that DTC, which would help point to more detail of where the fault may lie:

288, 289, 290, 292, 294 and 501.

 

Thanks for these excellent call outs.

Posted via the PriusChat mobile app.

 

Our Gen 2 (2008) Prius has always struggled with hills like out in Cali when we would drive from the Bay Area to Lake Tahoe ever since we got it in late 2014. Struggles to maintain 45mph up long climbs, etc. but does fine in the flats. It has never thrown any codes otherwise though, but I figure it's a combination of it's aged HV battery and possible loss of compression or worn engine (last I checked it leaked about a quart every 1000 miles and the oil consumption started out of nowhere despite my meticulous oil changes and other services I do frequently. As far as I've read into it it's pretty much par for the course though.) I run all my vehicles pretty hard though which I know doesn't help, like 80-95mph on highway commuting in the Bay Area with 65% or more highway miles. We tend to get 32-38 MPG these days but I'm pretty sure it got a little better MPGs when we first bought it ~100k miles ago.

 

My prius(2009) has a huge noise coming from electric engine area. My mechanic told me that its coming from transaxle area. But the thing is there is no check engine light or any codes and transmission is changing very smoothly. I still drive my car like that but I need to find out the solution to fix it. Is there anybody had this problem before?

 

The huge noise probably is a failing bearing and you can drive the car as is for a while. A mechanical problem of that nature will not log a fault code. However you may want to check the transaxle ATF level at minimum or even better, replace the fluid now.

 

You're correct. I have worked on highlander hybrids that had that noise. At the end, itbwas a failed bearing that needed to be replaced.

 

Lately during this past hot summer, was making several trips up to Lake Tahoe from the bay area. I have a rebuilt battery and even with a good charge would have to pull over once to make it without really pushing the car. It currently at 230k+ [I put on around 50k a year in miles, no it's not used for Uber either] and still gets above 45mpg despite like you said a number of years driving at speeds to avoid the commute pile up.

The worst thing is my Inverter pump went out, I had decided to do a preemptive change in December, and the fake Toyota pump didn't last.

The only issue I am having now (besides the paint degrading like crazy) is a brake pad that wears quickly and what I get the feeling is a bad wheel bearing.

 

Hi Bob. As you are the tranny oil expert I hope you can help me. I recently flushed my transmission fluid by accident (don't ask). Much exited. When I try to refill it overflows as if the tank were full. Is this a physics issue? I have a leak and have added fluid in the past, without trouble. The car is tipped back so I would expect the fluid to flow away from the plug. The car is cold when I attempt this. I have also run from drive to reverse a few times, hoping this might help. It seems to shift as usual. Any ideas?

Thanks for your time.

Paul

 

This is why I always drive well below speed limit on steep passes. The only time I had my hybrid battery completely discharged and engine roaring for a long period of time was going up Vail pass in Colorado with a passenger and a ton of luggage. It couldnt go near the speed limit. That was a real test for it. I had just bought my used 2005 and I was worried that the battery died. Obviously it was just under immense load and at high altitude.