ZVW30 Transmission Oil Analysis

I don't know enough to make a recommendation but if you are interested in DIY I wrote a procedure which is in post #35 of this thread: http://priuschat.com/forums/gen-iii...ng/72896-diy-transmission-fluid-change-4.html

It is pretty easy and I had no problems.

 

I have no doubt that an early transmission oil change or two to get get rid of any manufacturing swarf and wear-in material is a good thing.

I have my doubts about the benefits of changing transmission oil to maintain viscosity. I'm willing to bet that Toyota's gear designers designed the gear sets and selected the transmission fluid with fluid viscosity reduction over the recommended fluid service life in mind.

The key bit of information we are lacking is what change interval the designers would use if it were their personal car. I suspect they would select a shorter interval than the what manual (marketing driven long change intervals) recommends , but not try to keep the viscosity near virgin transmission fluid numbers.

 

Based on Tumbleweeds analysis, I'm with Bob on this one.

I'm looking at a 20K initial and every 30K for the life of the car.

I've learned something important over the years, life time fill means life time of the warranty not the car.

Since I put less than 9K miles on the car a year the added cost is minimal

 

in my 04 manual, i find inverter and engine coolant at 105,000 miles and every 50,000 after. but i don't see transmission fluid change. am i missing it?

 

I don't think you are. The Gen3 says to inspect it every 30K miles but nothing about replacing it. I don't remember for sure from my Gen2 but I don't think it specified fluid change either.

 

Toyota doesn't care if your tranny goes bad out of warranty.

Our ATF testing group (Bob is our leader) have had ATF lab tested in classic, Gen2, and gen3 Prii and found that it is typically only good for 60k miles in an 04 (that would be mine which will hit 180k miles at the end of this summer and get it's third refresh of ATF at that time)-09 Prius, and 30k miles in an 01-03 Prius.

You Ignore Bob's good advice at the risk of an expensive early repair of your transmission.

JeffD

 

not ignoring, just thought i read a post sometime in the past about moving the fluid change up to 60,000 from toyota's recommended mileage change. could be mistaken.

 

What do they base the 15% on? Is that for gear and engine oil?

 

I am very impressed with the work you have done and the data you are sharing with us. Thank-you for your work.

If I get ambitious enough to do some transmission oil analysis, I will use them too. I won't ask them any questions until I send in a sample, I appreciate a business like that taking the time to deal with individual do-it-yourselfers and don't want to overdo it.

 

sorry, didn't mean to confuse. by moving up, i meant sooner than toyota recommends. it's just that, looking through the owners manual, i can't find a mileage related change interval, only inspection?

 

This is true. I change transaxle ATF fluid at 30K mile intervals because it is easy and relatively inexpensive to DIY and hopefully this will enhance the transaxle service life.

The scheduled maintenance guide is also silent regarding the PCV valve. However, that valve will collect HC deposits over time so its not reasonable to expect it will last forever. (I change that valve at 75K mile intervals.)

 

I can't find a mile limit either.

I got to wondering what "Inspect Hybrid Transaxle Fluid meant." It's only a fluid level check and check for leaks at 30k mile intervals. No mention of checking the appearance or smell of the fluid or anything else that might be useful in determining the condition of the fluid.

From the 2010 Service Manual /Hybrid Transmission & Transaxle /Hybrid Transaxle Fluid.


3. INSPECT HYBRID TRANSAXLE FLUID

(a) Check that the fluid level is between 0 to 10 mm (0 to 0.394 in.) from
the lowest position of the inner surface of the transaxle filler plug opening.

- Stop the vehicle on a flat road.

- Recheck the transaxle fluid level after driving when exchanging
fluid.

- Insufficient or excessive amounts of transaxle fluid may be the
cause of some trouble.

(b) Check for leaks if the quantity of transaxle fluid is low.

(c) Using a 10 mm hexagon socket wrench, install the filler plug with a new gasket.
Torque: 39 N·m (398 kgf·cm, 29ft·lbf)

 

More than one year old since last post...
Finally my 3Gen reached 30000km (18600miles), I asked the dealer shop to change transmission fluid and provide me a sample of the old one. I'll try to analise it asap.

 

Sure do wish Mr Wilson was still on the this board

 

Many of us do, I considered him a good online friend and the most knowledgeable poster on this site.

I sent in my second transaxle oil sample a couple of days ago. I'll post the results when they come back.