Changing the PSD fluid?

yup both cars are Canadian but as far as I understand they are identical in every respect to the US model other than the speedo and the fuel consumption readout. Also there is a rumor that that is just a toggle in the setup with the THHT. But I have been unable to confirn that .

 

<div class='quotetop'>QUOTE(finman @ May 22 2006, 08:42 AM) [snapback]259176[/snapback]</div>

The inadequate and too long transaxle oil change interval suggests that maybe their test environment was not as stressful as what we have in the N. American continent and/or the engineering tolerances of the transaxle led someone to conclude that more frequent changes were not needed.

My wife asked the same question last night and I pointed out the differences between Japan and central-west Texas:

- Texas (and the whole midwest) has more airborne dust
- We tend to have much hotter temperatures in the States
- Theory and practice of the 'transaxle breather tube'

So along with the blind spots in the cabin, we can add some concern about the transaxle maintenance.

Bob Wilson

 

<div class='quotetop'>QUOTE(bwilson4web @ May 25 2006, 05:16 AM) [snapback]260840[/snapback]</div>

the breather tube I don't think has anything to do with the PSD section. As you noted that there was a vacumm on the diffy/psd when you went to drain it. I'm trying to get Ifixem to confirm that the MD's are not in an oil bath which is what I saw when I looked at the dissambled PSD in Lacey. If that is as I suspect your breather vent mod really won't accomplish much. Lots of assy lube has high levels of silicon in them as it's used as a emmulisifer and an anti foaming agent. Also there is a high percentage of silicon in silicone and the case half's are sealed with Toyotas orange silicone, and there is a lot of it inside the case where they join. I'm still waiting for my UOA results, but the fluid was still normal in apperance and smell. Gasket should be in at my parts guy and I have a case of T-4 in the shop. So when the UOA is in and if the levels are normal I'm going to wait for another 10Km, till I'm at about 40,000 km's.

 

I really can't see PnG doing any more "damage" to the fluid, because with the ICE off your turning one less piece of hardware in the PSD, the planet carrier is stopped so the planets are turning on their shafts on the carrier which they do when the ICE is running. There is a few instances when the sun is stopped and not driving MG1 when the ICE is running but for most of the time when the car is moving and the ICE is running the sun is turning. The reason for the pump is to supply oil to the bushing in the sun gear when the car is stopped and the ICE is running as it tends to pump the oil out of the ring gear so the bushing will run dry, by having the pump it forces oil thur the center of the armature in MG2 and down into the shaft of the planet carrier and if you look at the shaft when Mike is holding it you'll see the lubrication feed holes for the sun bushing and the planet gears. I've ordered the pump mod and filter from him but haven't heard back from him.

 

<div class='quotetop'>QUOTE(TucsonPrius @ May 13 2006, 03:07 PM) [snapback]254829[/snapback]</div>

Shawn:

For some reason WS is more expensive in your area than up here. I paid $35.

I would like to offer some tips in case anybody reading this jumps into it without understanding the "gotchas."

First of all, and I can't stress this enough, ALWAYS remove the fill plug first! If for any reason you pull the drain plug first, then can't get the fill plug out, you're screwed. I had a fairly difficult time getting my fill plug off, and I imagine it would be an easy plug to round off if you're not careful. Fortunately I have a good selection of 6 point sockets at my hobby farm and didn't fubar the plug.

If I recall, a T-55 will also fit the drain plug. That is what I used to remove my fill plug.

Second, it will be hard for most folks to get the level right if they have to use ramps. I built a large ramp at my hobby farm out of old railroad ties, so I was able to keep the car level while draining and filling it.

To fill it I used one of those gear oil pumps you use to fill an outboard lower unit. I picked up a new pump for $7 at Princess Auto and used it to pump the fresh oil in. If I recall, around 150ml is left behind in the 4 litre can

Third, it's just too easy to mistake the inverter coolant drain for the CVT fluid drain. Anybody know why Toyota didn't use the hex plug for the coolant drain??

j

 

got my UOA back on my Classic and with 31,000 km's on it the only reading that is out of spec is the silicon reading which was 204 PPM and it was also noted on the reply that it's probably non-abrasive assembly compound or grease. All other readings were in the normal range execpt for the Fe (iron) reading and that I created when I did the sample as I just back off the drain plug and let it slowly fill the sample bottle. So the 58 fe reading is probably not a problem.

 

at work we us SOS which is a division of Finning Tractor ( largest Catapillar dealer in NA ) and they have a small sample kit which contains a small bottle and the tracking numbers and you fill in your data make model unit (transmission) and mileage/hours and send it in and they do the analysis and send you the results. My cost is $17 They even do soot, which in my case was 0 PPM. V100 is 5.5 and V40 is 27.3
V100 is viscosity at 100C
V40 is at 40C
so 5 weight at 212F
and 27 weight at 104F
The oil sample that I took looked and smelled like normal ATF/Dex111

 

<div class='quotetop'>QUOTE(hdrygas @ May 29 2006, 08:57 PM) [snapback]262615[/snapback]</div>

If you want to contact Bob Wilson here, Green Hybrid, or the Yahoo technical group, he is also doing trans fluid analyses. I had mine changed (but not analyzed) back in the old days before we were so concerned. But at least there were no ferric flakes on the magnet.

Frank, no doubt you know that the trans is glued shut with red RTV, so that would be a probable source the first time around.

 

<div class='quotetop'>QUOTE(tochatihu @ May 29 2006, 09:45 PM) [snapback]262633[/snapback]</div>

it's quite possible that the silicone adhesive is the cause but as Finning noted it could also be an assembly lube that is the source. What will be interesting is to see on the next sample after a drian and fill, if the silicon levels are still high. I will hazzard a guess is that it'll be really low as I suspect that it was an assembly lube that is the source. With the readouts that I have from the sample I'll wait at least another 10,000km before doing a change. Even though I have a pan gasket and a case of T-IV I just don't see a problem at this point and it should go at least another 6,000 miles no problem.

 

<div class='quotetop'>QUOTE(Frank Hudon @ May 30 2006, 07:29 PM) [snapback]263081[/snapback]</div>

The 'silicone adhesive' is an interesting hypothsis. I'll ask my oil testing service if they have any insights about this. I also found this interesting article:

http://www.practicingoilanalysis.com/artic...minationControl

BTW, I will point out that my second change still had a significant, 40 ppm, silicon load BUT I had not dropped the pan and wiped all exposed surfaces to remove the residual debre. I will point out that the iron and copper loads were significant as well as the particulate count. Since in the second change, I actively cleaned all easily reached surfaces, I'm expecting a substantial reduction in silicon, iron and other wear materials on my next change. The only areas not cleaned were the unexpected gallery found to the rear of the transaxle and the barrel of the oil pickup tube . . . next time.

Thanks,
Bob Wilson

 

Another Prius owner in Plano TX sent me a sample from his, 44k mi., 01 Prius and the top contaminates were:
258 ppm Silicon
116 ppm Iron
067 ppm Copper
046 ppm Boron (?)
017 ppm Aluminum
015 ppm Nickel
012 ppm Sodium
26.6 / 5.2 Viscosity 40 (C ) / 100 (C )

On my 03 Prius from Fort Worth TX, the top contaminates were:
227 ppm Silicon
075 ppm Copper
069 ppm Iron
043 ppm Boron (?)
021 ppm Aluminum
26.1 / 5.2 Viscosity 40 (C ) / 100 (C )

The reference sample tested with no contaminates and this viscosity:
35.3 / 7.4 Viscosity 40 (C ) / 100 (C )

Two samples are not enough to document a problem but the data suggests:

1) silicon contamination with wear products of copper, iron, boron (?) and aluminum
2) severe viscosity reduction

The boron suggests coolant contamination. However, no water was found in the fluid. This remains a puzzle.

Bob Wilson

 

<div class='quotetop'>QUOTE(bwilson4web @ Jun 5 2006, 04:58 PM) [snapback]266323[/snapback]</div>

Add this to your list
Fe=58
Si=204
Cu=31
B=44
Ca=162
Al=14
P=261
Oil condition
St=0
OXI=38
Nit=5
Sul=28
Water=0
Antifreeze=0
SOS flagged the Fe Cu and Al along with the Si but noted on the return that it could also be from non-abrasive assembly lube or grease. I think that it's not a real problem or we'd be seeing diffy failures now with some of the higher mileage G1's. Boron and Phosphorus are oil stabilizers (additives) so there in normal atf as well. As I said my sample was normal in colour and smell.

 

Bob that was a most interesting article on Oil Analysis. Leads me to believe that it's probably leaching from the sealants. I'd love to know what all Toyota uses as the cork stabilzer on the pan gasket as it's cork but you can hardly compress it and it's nice and pliable. Possible silicone based adhesive injected into it to hold all the cork particles together? But as were starting to see all the Prius have elevated Si levels and no major failures piling up tells me it's not Silica. My best quess, leaching.

 

Hi Frank,

<div class='quotetop'>QUOTE(Frank Hudon @ Jun 5 2006, 08:48 PM) [snapback]266387[/snapback]</div>

I've updated the testing results:

http://hiwaay.net/~bzwilson/prius/pri_T_cold.html#TRANSAXLE

Working on the hypothsis that the silicon came from outside the transaxle, I made a modification to eliminate the negative internal pressure and provide a filtered source of air:

http://hiwaay.net/~bzwilson/prius/pri_vent.html

The silicon in the oil samples may come from gasket material, sealants or assembly lubricants. If so, once I get the current silicon levels down, putting a transaxle breather plug back in should have no effect on subsequent silicon loading. Testing the effectiveness of my breather tube modification is going on in parallel with my other studies. I am really after getting a handle on the other wear metals; viscosity changes; and transaxle oil temperature management.

This fall, I will have about 10-11k miles on the current oil and will change and test it again. For this recent change, I wiped the pan and exposed surfaces but missed one discovered gallery and cleaning the inside of the oil pickup tube. Based upon the pan cleaning, early flush and normalized transaxle pressure, I anticipate a substantially reduced silicon level this fall even though there will be more miles than the 7,000 from the latest change.

In addition to reducing the silicon load and other wear metals, I'm trying to find how many miles before getting a significant viscosity change as well as monitoring the transaxle oil temperature. BTW, upon review of the virgin, Type T oil analysis, I am no longer worried about the boron . . . the Toyota Type T oil is the source.

We know the transaxle is 'sling' cooled by the oil. The rotating parts sling the oil which wets and transfers the heat from the coils. However, a significant particulate load in the oil will make it a lapping compound. Upon disassembly, I would expect to find the directly exposed coils and metal surfaces 'polished' and the reverse sides fairly intact.

GOOD LUCK!

Bob Wilson

 

I had a good close look at the unit that Mike had a Lacey and with 150,000 miles that whole unit look in good shape. Other than the burnt coils in MG2, no obvious wear patterns etc. I suspect that part of the copper is from the bushing in the sun gear that runs on the input shaft/planet carrier from the ICE. I've seen diffy UOA's that have that much copper in the test results from the thrust washers under the spider gears. I'd also like to get an analysis of the red silcone sealant that Toyota uses. If you ever get a chance to "play" with some of that stuff you'll soon realize it's not like normal Dow Corning RTV silicone. It's more for lack of a better word...gummy.

 

I would think the silicon in RTV is very inert and tightly bonded in the structure. Is there a possibility that Toyota uses large silicon content in the aluminum alloy for the PSD case and what you see in the analysis is any casting residue, metal flash, etc that has worked loose? Just a thought, glenk

 

Hi folks,

This is what my oil analysis service reported:

Bob,

I would tend to agree with your assessment. Normally, you don't see high wear metals unless contamination ingression has occurred. The silicon adhesive and the grit/sand would both be indicated by the silicon levels. Normally, if silicon adhesive is the culprit the levels are on the low-end. At least this has been our experience. If your equipment manufacturer is using an adhesive then the levels may be higher than what we typically see. It may be worth consulting with them to see what level of silicon "contamination" can be expected from their process.

Also, if it is a dirt-based contaminant, you typically see aluminum in conjunction with the silicon. The typical ratio is 1:3.4(Al:Si). We don't always see an exact correlation with this ratio. The fact that you are also seeing aluminum contamination could be indicative of the silicon material being grit/sand. The fact that the ratio is much lower could be an indicator that the silicon is coming from an additional source such as an adhesive. It could also be that the grit/sand has a slightly different ratio than what we normally see. Bottom line - silicon adhesive contamination may be a possibility especially if the manufacturing process results in high levels of silicon once the equipment is exposed to lubrication.

I hope this info helps. Let us know if you have any additional questions.
Thanks.

Charles

-----Original Message-----
From: Wilson, Robert J
Sent: Monday, June 05, 2006 5:19 PM
To: charles
Subject: RE: Analysis Data - 1 Sample (Viscosity Index Included)



Some of my fellow Prius pilots had suggested a "silicon adhesive" used in manufacturing might have caused the high level. Based upon the wear metal counts, I pointed out that grit/sand makes more sense. But I am curious what might indicate a silicon adhesive?

Thanks,
Bob Wilson

It is not uncommon to find two sources of simular observations. Too bad we don't have a 'virgin sample' from a brand new Prius. If the silicon levels are high in the oil of a new Prius that would support the sealant / assembly hypothsis. But we still have the problem of wear metals and in my first sample, significant particulate counts.

Bob Wilson