Hi all, Finally got around to getting my Redline D6 fluid uoa'ed. Sent them to Wearcheck.com. $ 48 for 2 samples. There's 2 D6 pdf's. One is a sample with 25,000 miles on it which I installed when the car reached 5,000 miles. The other is a baseline virgin sample. The 25K wear metals & viscosity looks very good. The Tan is a little high and it has elevated silicone which we have seen before in other samples. But based on this I will check again at another 20K miles. The virgin sample shows minute moisture which I'm sure was condensation from sitting in a test plastic jar in my garage for 6 months. And it looks like they have a boron/phos pack in it too. That 25k sample sitting for so long also may have affected the tan/acid too. Next check will be sent off quicker. Tonight I will move this post up to the transaxle analysis area.
Thanks for sharing! It looks like the lab missed one important measurement: viscosity at 100C for the 25K sample. They did do it for the virgin sample. Copper showing up in the 25K sample may be a concern.
The used ATF fluid viscosity has declined from 33.01 to 26.54 which is a 20% reduction. My used ATF fluid testing showed a 15% viscosity reduction after 30K miles which is why I change the fluid at that interval. The Fe contamination is less than I would have expected to see.
That 20% reduction jumped out at me too. Is that 15% viscosity reduction number the recommendation from the oil analysis lab that Bob W used? I would think that more viscosity reduction than the Toyota recommended fluid is a sign of a problem with the fluid, but I also question whether or not 15% is a meaningful number. IIRC, Toyota calls for a fluid change at 100k miles on the Gen II and never on a Gen III. If I were in charge of their transmission design, I would design for the viscosity of fluid that had already sheared down to the point where the rate of shear declined. By dumping fluid because of viscosity loss at 30k miles, you may be dumping the fluid just as it gets to the viscosity the transmission was designed for. That my be a moot point, because contamination builds up with high mileage too and no amount of contamination is beneficial.
Thanks for the thanks guys and XS650 I agree with you. I am not so concerned by viscosity as I would be for poor metal wear numbers which seem to be pretty good. I hope Bob see's this post and weighs in also. If he's still here.
Repost your results in the Yahoo "Prius_Technical_Stuff" and Hybrid Car Forums discussion groups if you want comments from Bob. JeffD
Yes, I used the same testing lab as Bob. 15% reduction is the point where they suggest the fluid should be changed. Actually the Toyota maint schedule does not require a transaxle fluid change on 2G operated under normal conditions, at any mileage. It only requires periodic "inspection". Good point about whether the transaxle is intended to be operated at a viscosity 15% below the virgin fluid level.
IIRC, this is not the first report showing a significant drop in viscosity for Redline D6. I also happen to be using this in my Gen II car.
