Transaxle Oil Analysis

The transaxle requires close to 4 liters of Toyota WS-ATF, and it is important to use that. There are some alternative fluids in the US (Redline products), but you would be recommended to use the Toyota brand.

 

That's just their way of telling you that you shouldn't pay attention to anything they say.

 

I used Wally Worlds Supertech Dextron6 , say good for WS. I can tell you they both have the same funky chemical smell, and must be similar. Changed it at 70k, and right away I could see the engine would charge my 200v battery right up fast. Don't know what changing it did, but I like it. The viscosity seemed the same,dip my finger, and get 6 quick drips from both fluids, so who knows. The thing explodes, I drive my Grandprix.

 

Just had the transaxle fuid changed and tested again on 3/28/14 at 111021 miles. New figures are in 1st column, last column are from previous test detailed in a previous post. For some reason, couldn't edit that post:

Iron Fe ppm 25 175
Chromium Cr ppm 0 3
Molybdenum Mo ppm 0 0
Aluminum Al ppm 8 54
Copper Cu ppm 5 26
Lead Pb ppm 1 2
Tin Sn ppm 1 3
Silver Ag ppm 0 0
Nickel Ni ppm 0 8
Vanadium V ppm 0 0
Titanium Ti ppm 0 0
Manganese Mn ppm 0 5
Cadmium Cd ppm 0 0
CONTAMINANT ELEMENTS
Silicon Si ppm 18 195
Sodium Na ppm 0 7
Boron B ppm 45 35
ADDITIVE ELEMENTS
Magnesium Mg ppm 0 3
Calcium Ca ppm 129 103
Barium Ba ppm 0 19
Phosphorus P ppm 254 221
Zinc Zn ppm 11 37
NON-METALLIC CONTENT
Water % vol Nil Trace
Solids % vol <0.1 <0.1
LUBE DATA
Viscosity @ 40'C cSt 23.0 21.7
Viscosity @ 100'C cSt 5.5 4.7
ADDITIONAL TESTS
Viscosity Index 191 139

 

Please confirm this table:

	Column 1	Column 2	Column 3
0	[tr][th]service date [th]03/28/2014[th]06/10/2010
1	[tr][th] OD miles [th]111	020[th]70	598
2	[tr][td]Iron Fe ppm [td2]25[td2]175
3	[tr][td]Chromium Cr ppm [td2]0[td2]3
4	[tr][td]Molybdenum Mo ppm [td2]0[td2]0
5	[tr][td]Aluminum Al ppm [td2]8[td2]54
6	[tr][td]Copper Cu ppm [td2]5[td2]26
7	[tr][td]Lead Pb ppm [td2]1[td2]2
8	[tr][td]Tin Sn ppm [td2]1[td2]3
9	[tr][td]Silver Ag ppm [td2]0[td2]0
10	[tr][td]Nickel Ni ppm [td2]0[td2]8
11	[tr][td]Vanadium V ppm [td2]0[td2]0
12	[tr][td]Titanium Ti ppm [td2]0[td2]0
13	[tr][td]Manganese Mn ppm [td2]0[td2]5
14	[tr][td]Cadmium Cd ppm [td2]0[td2]0
15	[tr][td]CONTAMINANT ELEMENTS
16	[tr][td]Silicon Si ppm [td2]18[td2]195
17	[tr][td]Sodium Na ppm [td2]0[td2]7
18	[tr][td]Boron B ppm [td2]45[td2]35
19	[tr][td]ADDITIVE ELEMENTS
20	[tr][td]Magnesium Mg ppm [td2]0[td2]3
21	[tr][td]Calcium Ca ppm [td2]129[td2]103
22	[tr][td]Barium Ba ppm [td2]0[td2]19
23	[tr][td]Phosphorus P ppm [td2]254[td2]221
24	[tr][td]Zinc Zn ppm [td2]11[td2]37
25	[tr][td]NON-METALLIC CONTENT
26	[tr][td]Water % vol [td2]Nil [td2]Trace
27	[tr][td]Solids % vol [td2]<0.1[td2] <0.1
28	[tr][td]LUBE DATA
29	[tr][td]Viscosity @ 40'C cSt [td2]23.0 [td2]21.7
30	[tr][td]Viscosity @ 100'C cSt [td2]5.5[td2] 4.7
31	[tr][td]ADDITIONAL TESTS
32	[tr][td]Viscosity Index [td2]191[td2]139

Thanks!

Bob Wilson

ps. To see the table formatting, quote this post and use the "A A" icon in the upper right to see the raw tag text.

 

Very nice. How'd you do that? Original post for initial data was Transaxle Oil Analysis | Page 9 | PriusChat.

 

The Fe and Al reductions suggest the carry-forward from a change is about just under 15%. This is consistent with numbers I got with our 2003 Prius.

The Cu numbers suggest some is coming into solution but the source is unknown. Absent any collaboration metrics, I will speculate that yellow metal, bearings, perhaps in the power split device or silent gear. But this is pure speculation and remains a puzzle. However, the harder Fe and Al in suspension may be working as a lapping compound that removes layers of bearing material.

The Si numbers are interesting because we know this comes primarily from transaxle sealant. In the initial service, the sealant continues to cure and small bits 'break off' and go into the oil. But one of the functions of oil additives is to help settle suspended particles into bottom sludge, away from the moving parts. Speculation on my part due in part to previous analysis of sludge from our 2003 Prius, transmission pan, I suspect the 'flocculant' additives may be more effective in removing the sealant matter.

Bob Wilson

 

Thanks, Bob. We'll see if these trends continue for the next 60K miles. So, did you insert the tags manually into my post to get the nice formatting, or is there an easier way to do that? I'll be wanting to do that in 4 or 5 years, I expect. Now knowing what the tags are, I could do it in Excel pretty easily, but I'm sure there's a better way.

 

I use the excel "concatenate" function but similar functions exist in other spreadsheets.

Bob Wilson

 

If it can't be done in Excel, it's not worth doing.

 

Recently changed the ATF on a 2008 Prius purchased for my daughter. This was the first fluid change at 72,900 miles. Fluid was very dark compared with new (photo attached). Blackstone report is attached. Their comments:
Wear metals and silicon were fairly high in this first sample from your Prius's transmission, but given that this was a fairly long oil run (averages are based on just ~45,000 miles of oil use), and that it's the factory fill of oil, we doubt there's anything to be too concerned about here. The metals may just show wear-in from when the transmission was new, and silicon is from sealers.
I will change the fluid again in 30K miles.

 

Mine was changed at 60 odd thousand and was similar to the photo above. It needed to be changed at that stage. I will change again at 100k ish

 

Can anybody give me a sense of how much getting the ATF changed should cost? I was just quoted $320 for a transmission flush, plus $80 for transaxle fluid at my local non-dealer shop here in Seattle. FWIW, I'm driving a 2005 Prius with ~65k and this would be my first transmission/transaxle fluid change.

 

You don't need a flush, just need a fluid change. Flushing is actually not a good thing to do. The dealer will charge you about $100 to $120. If you get it done elsewhere, make sure they use the ATF WS fluid from Toyota.....

 

4 liters of the fluid and two replacement washers cost me just under $40, from the Toyota dealership parts department. The labour for someone working with a proper hoist (unlike me) would not be over an hour, and the procedure is very simple. So like JC91006 said.

If you're at all mechanically inclined, have a decent area to work with floor jack and safety stands, it's on par with an oil change, a little different but no big deal.

 

Draining and refilling the fluid took my mechanic less than 10 minutes from start to finish, it would have been quicker only I was chatting to him whilst doing it!

I bought the WS fluid from Toyota myself at less than trade price and he charged me about €25 iirc. Good for another 50-60k miles

 

Thanks for the replies gang. I opted to just take it to the dealership for service. Quote was around $80. Much more reasonable.

 

I changed my transaxle fluid 2 days ago at 72.6k miles. This was the first ATF fluid change for my '05 Prius. Thanks to all the great pictures and guides here on PC, it went very smoothly.

The old fluid seemed to be a reddish brown color. I will post pics comparing the old vs. new fluid shortly (probably tomorrow night). I will also be sending in a sample for analysis and will post the results when I get the report from Blackstone Labs. Many people have contributed to the knowledge available on PC by having their ATF fluid analyzed, so I figured I'd do my part to help others decide if and when to replace their transaxle fluid.

Many thanks to all those that have contributed to this thread.

Edit: Here's a side-by-side comparison of the ATF fluid I drained with new ATF fluid. In each photo, the used fluid is on the left and the new fluid is on the right.

Viewed in the sun


Viewed in the shade


I didn't realize how profound the apparent difference between the two fluids was until I placed them side-by-side. Toyota may regard ATF-WS as a "lifetime" fluid, but I'm glad I changed mine.

 

Late last month last month, I changed out my ATF fluid & sent a sample in for analysis. Attached is a copy of the report from Blackstone Labs.

Compared to the universal averages, my sample was high in aluminum, chromium, iron, copper, tin, nickel, sodium, manganese, potassium, silicon, magnesium, zinc, and barium. Viscosity was within the normal range.

Feedback from the lab guy:

Thanks again to everyone that has contributed to the knowledge base concerning the Prius transaxle fluid that myself and others have benefited from, and feel free to chime in with questions/comments.

 

No reason to drive around with all that crud for 76,000 miles though. I know, stating the obvious.