TunedRX300

Oil Analyzer sent the transmission fluid UOA. This is the first drain and fill after I changed 7 quarts of my AWD tranny to Amsoil Universal ATF with the procedure detailed in the photo DIY .

I want to thank hitthepin, he donated the UOA kit to me. Together we want to make this lab report avaliable since everyone is interested in scientific report.

51847 miles on the Amsoil. TAN is 2.19, ATF is sheared to 5.99 (or 88% of virgin ATF). Iron and Boron are high for first glance but when I look at this 2005 Highlander UOA, wear metals in PPM are accumulating at even faster pace on Toyota T-IV.

I feel comfortable to let my tranny to ride 50K change intervals with Amsoil since there is no slippage at all.

code58

Thanks TunedRX- Being a detail person I am always interested in the details! LOL Appreciate those that take the time to report on fixes, tips, experiences, insights, new ways to approach old problems, etc., etc., etc. That's what makes the forums great. Always disappointing when someone comes for some brainstorming on a problem, and you never hear from them again. Never know whether they were able to take care of the problem, found the answer on the forums or fell down and couldn't get up! LOL

TunedRX300

Actually Lexmex is the best at following up with some very detailed pictures and reports. He is also the one who made the DIY a sticky

Here are where these wear metals came from. Tranny is enclosed, so metals stay in the system until drained, they tell us how the tranny fares over the last ATF change interval.

thomas1

So than am I assumming that if there were high amounts of Aluminum that maybe the Planetary gear assembly could be going bad? The original carrier is a 4 gear aluminum assembly with steel gears. If the carrier starts to wear and causes the gears to float, than we would have the failure that most of these transmission experience..

lexus114

++++++++ 1 ^^^^^^^^^^^^

TunedRX300

Our tranny has more wears, I don't know it is soft metals or just the gears are demanded to do more than other designs.

The aluminum and iron are definitely coming off, most of these fine particles are suspended in ATF, which is what ATF meant to do (vs. letting it settle, clog, and restrict ATF flow).

The chemical property of the ATF will replenish when 40% of the ATF is changed. I can not confirm it but it could be the reason that Toyota design 4 quarts out of our 9.8 quarts capacity to be drained and filled.

The physical property of old ATF will not be changed much with relatively low% of ATF replaced, once the fluid is sheared (rule of thumb discussed is 25% below value of virgin ATF) it need to be replaced. ATF will also be oxidated when tranny cooks it.

In short, either change of chemical, physical property or large amount of metal debris call for change of ATF. It appears that 50K is safe (to my standard and usage) with Amsoil ATF.

thomas1

Maybe when the planetary gears, which are supported in an aluminum carrier starts to wear ie the gear post in the aluminum wears the aluminum, than the gears dont mesh perfectly (I know thousands of a inch) and that is when we see both steel and aluminum in the readings. Sorry design trying to support a steel gear in an aluminum casting.....You have seen my report that the replacement at independent shops at least is a steel carrier supporting the gears. This would give it a greater deal of strength...

TunedRX300

Thomas,
Thanks for sharing. There is a Toyota Tundra UOA, the wear is much lower (found in metal in ppm) at given miles. Of course, Tundra tranny and engine are better built than the RX300.

I copied and pasted the UOA of 2005 Highlander UOA, high Fe, Al and Cu were also found. The owner used another lab so this gives more support that it is our tranny design that may cause some of failures reported.

This Highlander did worse in wear metal accumulation rate with Toyota T-IV than what I reported. The owner said it is his wife drives the SUV and 60% highway miles (those miles are the easiest on tranny).

thomas1

Great info, Thanks TuneRX300. Well I may look up that AMSOIL dealer.