Transaxle Oil Analysis

Attached is the Blackstone analysis of my 2007 Prius at ~18,000 miles (17,995). This was the factory fill.

 

A couple of questions:

• color?
• transparency?
• smell?
• region of country?
• typical highway speeds?
• % of driving at or above 45 mph?
• duration of car ownership?

Thanks,
Bob Wilson

 

wow i knew it, Toyota is way too generous with that 96,000 km / 8 year change limit... I'm glad i change mine every year. I wonder if the test results for normal car that uses the same fluid applies.

 

You know, as hard as the HSD gears work, I would change mine at 50k, minimum.

 

Color - Red, looked pretty good
Transparency - Fairly opaque
Smell - No burnt or otherwise nasty smells - close to virgin WS

I live in NJ (NYC metro region)

Highway speeds are generally 65MPH and lower. When I drive I set the cruise control for ~58MPH

The car is a suburban "mommy" car with mostly very short trips (3 yellow bars or less). We owned the car since new, March 2007.

Rumple

 

Excellent practice!

IMHO, you can probably go 60k miles with the new oil without a problem. With the change, the high metals will have dropped significantly. I was a little worried about their report on particulates but that could be just the limits of their equipment.

The only item that bothers me a little is "opaque." I suspect we have micro-dieseling going on but this is best diagnosed by getting a handle of the combustion products in the oil including a growing acidity. But as long as it smells like oil and not paraffin, I suspect you're going to be in great shape.

GOOD LUCK!
Bob Wilson

 

Here are my readings: 2007 Prius, service date November 2007, 35000 miles, factory fill transaxle oil, Blackstone test results after change in November 2008.

• color - Red
• transparency - Pretty clear, nothing floating or cloudy
• smell - Like transmission fluid
• region of country - NE USA
• typical highway speeds 70 mph, 2 - 3 hours per day or trip
• % of driving at or above 45 mph - 80% or more
• duration of car ownership - 1 year

MI/HR on Oil 35,000
MI/HR on Unit 35,000
Sample Date 12/03/08
Make Up Oil Added 0 qts


ALUMINUM 42
CHROMIUM 2
IRON 87
COPPER 15
LEAD 2
TIN 5
MOLYBDENUM 0
NICKEL 4
MAGANESE 3
SILVER 0
TITANIUM 0
POTASSIUM 1
BORON 49
SILICON 178
SODIUM 4
CALCIUM 116
MAGNESIUM 3
PHOSPHORUS 269
ZINC 8
BARIUM 21

SUS VISCOSITY @ 210 'F 41.9 42-51 normal range
cST VISCOSITY @100 'C 4.75 4.8-7.9 normal range
FLASH IN 'F 360 >335 normal range
FUEL % -
ANTIFREEZE % -
WATER % 0.0 <0.1
INSOLUBLES % TR <0.1

Blackstone's analysis said this was great data.

 

I think I may have overstated this - it looked like the virgin WS only a darker red. Nothing milky or the like.

For increasing the probability of getting more longevity out of a transaxle, it would seem to me that at least an initial short (<20K miles) interval change is worth it to get out the break in wear. Most likely I'll change again in 30,000 to 40,000 miles which for us is 3 to 4 years from now. Who knows, maybe by then Redline D6 will have returned a few good UOA and I'll use it instead of WS?!

Rumple

 

We have a 2002 Prius. changed transaxle fluid at 60k. maybe b4 that too. at 85k, transaxle gone. warranty expired 9/14/08. this happened 10/8/08. toyota is basically saying 'tough'.

i recommend changing fluid much more frequently. art's automobile in calif recommends replacing it at least every 30k. he actually suggests replacing all fluids more frequently.

difference: older prius uses t4 fluid in transaxle. newer ones use WS (world standard).

$8k to fix car. I think fifty bucks to replace fluid and keep car running is a better option.

Peggypa

 

Hi Peggy,

That's very unfortunate. Have you contacted the Toyota Customer Experience Center to determine whether you can get financial help on the repair? If that is not going to happen, then have you looked into the possibility of purchasing a salvage transaxle and getting an independent mechanic to install?

 

Patrick,
yes, i did.
at the same time this happened (transaxle), Firestone overfilled my oil by one quart on 10/3. car failed 10/8. firestone took out extra oil. next morning extra quart still there when towed to toyota. toyota says it's coincidental. without letter from toyota, firestone says too bad. i could hire a lawyer is toyota's care position. I bought a rav4 to replace the Prius. I can no longer recommend a Prius. 3 weeks. that's how long my warranty expired b4 this happened.

Peggy

 

Hi Peggy,

Thanks for the additional info. Did you trade in the Prius on the RAV4?

Overfilled engine oil should have no effect on the transaxle longevity.

One clarification: unless you purchased extended warranty coverage the transaxle is covered by the drivetrain warranty. That warranty is for 60K miles or 60 months whichever comes first. If you did not have extended coverage then it seems that your warranty had expired 25K miles ago.

 

Could you describe the symptoms when your transaxle failed? I'm very interested in all of the actions taken in the debug and diagnosis.

Where is the Prius now?

Thanks,
Bob Wilson

 

Seems like I'm preaching to the choir, but I just changed my fluid at 55k. I guess it was mechanically fine, but it did not look like happy stuff. Dark brownish-purple color. Made me feel good about the $30 and one hour I spent changing it. (Went with the OEM WS fluid) I'll get a UOA from Blackstone.

 

Given the history of UOAs that has been built up on the Prius so far, this was mostly likely a good idea for increased probability of transaxle longevity and reduction of issues. It is also easy and fairly inexpensive to do.

I also went with the Toyota WS fluid, although I gave a good long thought to going with Redline D6.

Rumple

 

Where do you buy synthetic WS?

 

I get mine at the Toyota parts department.

Bob Wilson

 

Gee. Another thing to worry about. How hard is it to DIY? Thanks!

 

Don't worry 2009. Use the PC search tool

http://priuschat.com/forums/gen-ii-...bleshooting/44124-changing-transaxle-oil.html

You need a funnel and some plastic tubing. You need to open the top bolt (fill hole) first. You need the proper tool to open the drain hole.

I have not seen any suggestion that the NHW20 should be first changed before 30k miles, so perhaps it's not your time yet.

 

Just a note, I'm about a year into my fill with redline D6 transaxle fluid and my car is working perfectly. I'm now at 55K miles, I have not taken any fluid back out yet to test, but I plan another change later this summer. I getting a consistent 55+ mpg in New England with steady highway driving.