Changing the PSD fluid?

<div class='quotetop'>QUOTE(hobbit @ May 1 2006, 09:48 PM) [snapback]248397[/snapback]</div>

The service manual has dissasembly instructions with decent pics, but toyota has never given techs fluid flow ckts in automatics. GM has hydrolic flow charts that look like wiring diagrams. GM also has techs inside the tranys more often than toyota. The flow is from the sump, thru a nylon micro screen, up a cross drilled boss to the pump and then to the planetary sun shaft for splash oiling. The trick is splicing in a cooler that is presurised, because on the PSD we can't just dump into the pan on the cooler outlet.
Regards, Mike

<div class='quotetop'>QUOTE(tochatihu @ May 3 2006, 03:29 PM) [snapback]249343[/snapback]</div>

I think you are more than 500 miles to Oly wa, but if you are crazy enough to drive here I'll put one in N/C labor. Since you are in a warmer climate than we are you would make a great prototype. I think anyone who can overhaul their sink can do this install with a 10mm wrench, some vasaline and a flat screwdriver in about 30 minutes. KISS.
Regards, Mike

 

While you're in there, can you offer any confirmation about how
the PSD and transaxle is lubricated [or not] during electric-only
driving? Does something really depend on the ICE to turn the
transaxle oil pump, as rumored, or does it turn with MG2?
.
Knowing this would help clear up a lot of debate about risks of
the plug-in kits.
.
_H*

 

Hi Mike,

This sounds good for avoiding heat stress:

<div class='quotetop'>QUOTE(IFixEm @ May 5 2006, 04:34 AM) [snapback]250130[/snapback]</div>

My wife has begun to get suspicious.

<div class='quotetop'>QUOTE(IFixEm @ May 5 2006, 04:34 AM) [snapback]250130[/snapback]</div>

I am also worried about the transmission oil getting too cool. The Dept. of Energy report indicates losses go up with colder transaxle temperatures and we already know MPG drops off way too fast in colder weather.

I believe the automatic transmission Echo has an ATF transmission coolant loop in the radiator. By replacing the Prius radiator with an Echo radiator, we can use it to handle the ATF fluid cooling in the summer and in the winter, accellerate the warm-up. The 108 HP Echo radiator should easily handle the 70 HP ICE load and whatever the transaxle wants to contribute. It would also simplify the plumbing and the regular thermostat would easily handle temperature regulation.

I have a 2001 automatic Echo and 2003 Prius. When you get the plumbing kit worked out, I would be happy to see about fitting an Echo radiator into my Prius and connecting up the transaxle coolant tubing. I've already opened the transaxle breather plug so we don't have to worry about negitive pressures.

Good luck at the show!

Bob Wilson

 

Just sharing some thoughts:

--- In [email protected], hobbit@... wrote:
>
> If you haven't seen it yet, . . . get over
> to http://priuschat.com/index.php?showtopic=19256 and chase the links
> to all the pictures.

Great photos!

> . . . Mike, aka IFixEm on PC, took apart a transaxle
> and brought it to the Lacey Alternative fuel festival to show off.
> These are better than the Argonne paper ones, and may actually give some
> hints as to what volumes connect to what in there. I haven't even
> finished going through them all yet...
>
> I also have a question in to IFixEm about this, which he hasn't
> answered yet.

Correction: the transaxle oil pump is engine operated - the short stub on the MG2 side of ICE shaft is too short to directly reach the oil pump but there is a shaft shown in pp. HT-44 that connects the pump to the planetary gear carrier. Since it is ICE driven, then when in EV mode, the transaxle would not have the oil pressure for 'sling' cooling. The slot in the MG2 side of the PDS ICE shaft engages the shaft extension.

Those two, tapped galleries just over the transaxle vent plug are now even more interesting. I could not see them clearly in the vehicle and have no idea what they may lead too but I'd sure like to know. This may be an addtional set of unused taps for either glycol or transaxle oil cooling.

The photos clearly show the heat stressed windings. This begs the question of how many thermisters are in the windings to measure the temperature. Just one?

There is another potential source for winding temperatures, the resistance change of the coils. Measuring the coil current and voltages is an area that I've already been doing some work in. I may change the goal to a per-coil, temperature read-out. The same approach would work for the MG1 coils.

As I was thinking about the problem of transaxle heat removal, it occurred to me that I can put a filtered, air port in the transaxle oil filler plug and draw heated air out the transaxle vent tube. There are several approaches including one powered from the latent heat removed from the transaxle. Unlike an oil only heat exchanger, this internal, cooling air flow would remove heat directly from hot, interior surfaces and will be easy enough to test.

BTW, you mentioned the ground loop detector being sensitive enough to measure 'water from an engine wash.' The cover plate for inverter MG2 leads has a small, black rubber, vent tube, otherwise unprotected, that points down to a flat plate. If someone were to try and wash a hot engine compartment, the cold water spray would 'chill' the box on the inverter and the cooled air would draw-in the ambient, spray filled air. In areas where salt is prevelent, it wouldn't take much.

Well, I've got a small resistor network to test for automatic temperature data collection. Then I need to go climb Old Fabius and see what happens.

Bob Wilson

 

Hv trans planets are ice oiled only and I do not think an elecrtic pump will work with ice off because the pump rotor is unable to spin. An electric pump would simply unseat the psi regulator after 15psi.
On venting the HV trans. Toyota M/T and diffs have for years not vented freely. They take a long time to vent as the veh cools down. I don't know why they do it but GM diffs are the same. I think the vent situation helps reduce leaks. If it's 13.7 psig inside the box and 14.7psig outside it wont leak.
Thehv hard parts will never shear and bearing failure is unlikely, but MG2 overheat seems possible, but still unlikely. Using air to cool the parts seems inefficent. Using a liquid is far more efficent. A person can stand outside in 52* air in thier underwear all day. They are dead in 90 minutes if it is 52* water. I called a local cust to bring in his 01 for a cooler retrofit for trials.
Regards Mike.

 

Hi folks,

I got the test results back on the AMSOIL ATF after 7,000 miles in use from Jan-April of this year with one 1,500 mile trip:

0k - 7k - 53k - usage - Test
37.3 - 33.9 - 26.1 - 30.4% - cSt@40 C
7.5 - 6.7 - 5.2 - 34.8% - cSt@100 C
174 - 159 - 133 - 36.6% - Viscosity Index

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

This data suggests ~10k miles and six months of similar use would bring the oil to the 50% level between brand new and horrible. Unfortunately, when I first changed the oil, I didn't drop the pan and wipe down all surfaces. But this change I also put in a filtered air vent in to reduce dust infusion. I'll probably do my next change in August along with some of the pre-heating and plug-in elements. I would like to have my first generation enhancements in by October.

NOTE: My oil testing service, PdMA, reported the oil viscosity was down 10%. Their threshold for a viscosity problem is -15%. Based upon a straight-line rate, that would be ~10-11,000 miles.

Bob Wilson

 

Hi Mike,
<div class='quotetop'>QUOTE(IFixEm @ May 8 2006, 12:57 PM) [snapback]251572[/snapback]</div>

I'm thinking more along the lines of circulating the oil through a radiator.

<div class='quotetop'>QUOTE(IFixEm @ May 8 2006, 12:57 PM) [snapback]251572[/snapback]</div>

My problem is the first oil test came back with a very high level of silicon and the suggestion that dust had gotten in the transaxle. If there is a leak, I want to find it, not suppress it while it sucks in dust and dirt. I can fix a leak but polishing the insides with dirt . . . not my car. <grins>

<div class='quotetop'>QUOTE(IFixEm @ May 8 2006, 12:57 PM) [snapback]251572[/snapback]</div>

The puzzle is if I circulate the hot oil through a radiator, only ambient air is around to take the heat away. But if I flow filtered air through the transaxle, it will pick up the heat directly and can be exhausted. The challenge is making sure the cooling air is well filtered first.

The one problem is humid air can condense water overnight. That is one hard nut to crack.

<div class='quotetop'>QUOTE(IFixEm @ May 8 2006, 12:57 PM) [snapback]251572[/snapback]</div>

Lucky duck.

Bob Wilson

 

I had been putting off changing the PSD fluid when this topic came up. So, today, with just over 39000 miles, I put it off no longer.
Picked up the 4l can of ATF-WS from toyota ($42.41, part number 08886-02305) and the two washers needed ($0.70 per, part number 90430-18008) and went to it.

First loosened the fill plug on the front side of the transaxle. This is a 24mm bolt and for me it was easiest to loosen it using a box-end wrench while the car was up on ramps. Checked and double checked that I'd be able to refill it with a funnel that had a long hose attached. Also loosened but did not remove, the drain plug while it was up on the ramps. The drain plug takes a 10mm hex.

Backed it off the ramps, removed the drain plug and fill plug and let it drain a good 15-20 minutes. As others have said the fluid was *very* dark, and quite a bit of shavings adhered to the drain plug. It was enough that I know I'll repeat this in another 40k miles. Replaced the clean drain plug with a new washer, torqued it down to 29 ft-lbs (per spec) and starded refilling. It took almost all 4liters of the new bright cherry red fluid.

After filling, replaced the fill plug with the *old* washer, drove it a bit, brought it back and topped off the fluid. The replaced the fill plug with the *new* washer and torqued it to 29-ft-lbs.

Over all, it took about 45 minutes from start to finish and was no more difficult than an oil change. As others have said, it's probably worth it to spend the $45 or so and just do it, rather than risk that $$$$ transaxle.

Thanks,
Shawn

 

Thanks for the transmission EZ fill instructions Shawn. Might be good to note that Art's Automotive, one of the few indy shops that does hybrids, recommends 30k interval transmission fluid changes for the classic Prius:

http://www.artsautomotive.com/Hybrid.htm

They may, as well, for the new model but I do not find service details for it on their web site.

DAS

 

Hi Shawn,

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

This is pretty much how I did my first transmission oil change. I too didn't drop the pan and clean the magnet and wipe down the surfaces. When the test results came back, I decided the first change would be a 'flush' and I would do the job right with a pan gasket and wipe down the next time:

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

Click on the "TRANSAXLE OIL TESTING" to see the results of just an oil only change after 7,000 miles.

My used Prius came from the Fort Worth Texas area and had a substantial load of silicon in the oil. I've made a modification to minimize future dirt infusion and until I have a good set of consistent results (say in two years), I won't be going back to the one-way valve, transaxle vent tube. By then, I'll also have a better handle on the transaxle oil temperatures.

BTW, an oil sample test with shipping costs about $25 and can give you peace of mind about the health and status. IMHO, it is like going for a physical and getting the blood tested too. But hey, whatever works for you.

Doug, thanks for the link to Art's shop. Initially I was wondering what an indianapolis race shop was doing with hybrids and then I figured it out. <GRINS>

Bob Wilson

 

I've looked and looked thru the Prius maintenance schedule booklet and it says to check differential oil and transmission fluid (TWO separate items!) at various mileage points (sorry don't remember exactly). Like 30,000, then 60,000, then 90K, etc. Nowhere does it say to REPLACE the PSD oil. And I'm assuming they are the same item? Diff oil and tranny oil? Just wondering if there is a definitive answer here.

What I'm calling the PSD (power-split device) is the 'tranny' or 'differential' in the maintenance booklet?

Thanks!

PS On the same note of replacing things...100K replace inverter AND engine coolant...120K replace spark plugs. These are from the same Prius maintenace booklet that does not say anything about the PSD lubrication. Any comments here?

 

<div class='quotetop'>QUOTE(finman @ May 20 2006, 03:41 PM) [snapback]258598[/snapback]</div>

page 24 in the 2k4 Owners Manual Supplement says Hybrid Transaxle Peplace fluid every 72 months or 96,000 Km's 96K=approx70,000 miles.
Edit
same page for the 2k3 Supplement Manual

 

<div class='quotetop'>QUOTE(finman @ May 20 2006, 05:41 PM) [snapback]258598[/snapback]</div>

The 2003 Maintenance manual, volume 2 calles it "Hybrid Transaxle" and incorporates the differential, PDS, MG1 and MG2. In any other car, it would be called the 'tranny' or transmission.

<div class='quotetop'>QUOTE(finman @ May 20 2006, 05:41 PM) [snapback]258598[/snapback]</div>

I first became suspicious when I noticed my MPG was not what I expected. Then I read three reports that indicated that transaxle efficiency made a significant impact on vehicle performance and Toyota added ball bearings to the next model, NHW20, transaxle suggesting this is an area of interest.

There was a Dept. of Energy report that indicated transaxle efficiency is dependant upon oil temperature. There was a Canadian fleet report that showed warm-up had a significant effect on MPG even though the engine warms up quickly, only the transaxle has no source of heat beyond mechanical energy from the ICE. Then a Dept. of Energy fleet report from Arizona suggested that the second year MPG was not as good as the MPG in the first six months yet oil changes typically would happen at least every six months. Only the transaxle fluid change was on a longer time period. Finally, a friend who is also a car enthusiasts had recommended synthetics for engine, transmission/differential and wheel bearings (not tested, yet!) This led to my first transaxle oil change at 53,000 miles and an eye opening oil test.

There is evidence that mechanics who have look closely at the transaxles are begining to see the value of more frequent transaxle oil changes. After all, it is the quality of the oil in the transaxle, not the words in a manual, that actually determines the efficiency and wear. I won't fault anyone who wants to 'go by the book' but I tend to pay attention to 'margin notes' and mine say, change it sooner, rather than later.

If you do change your transaxle oil in an NHW11, 01-03 model year, please send me a note because I want to test your sample. All I need to know is the model year and miles on that oil sample. We'll the work out the logistics of getting the sample to PdMA for testing.

Thanks,
Bob Wilson

 

<div class='quotetop'>QUOTE(hdrygas @ May 21 2006, 11:10 AM) [snapback]258855[/snapback]</div>

You pays your money and takes your chances. Good luck!

<div class='quotetop'>QUOTE(hdrygas @ May 21 2006, 11:10 AM) [snapback]258855[/snapback]</div>

My concern was heat stress to the transaxle oil because when it stops lubricating effectively, bad things happen to the rest of the parts. This from a Dept. of Energy study (Google up "ORNL/TM-2005/33"):

Bob Wilson

 

Hi folks,

I installed a signal cable from the engine compartment to the cabin via a fresh-air vent and a small hole in the AC filter. Initially, I'm manually recording the time and resistance and using a spreadsheet to calculate the temperature. The initial results are at:

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

This data shows that during a 29 minute commute at speeds of 25-35 mph, the temperature continued to increase over the whole route. This suggests that transaxle oil temperature, at least at 88 (F) is not a significant part of the warm-up energy loss. In fact, it appears to be a fairly constant rate of increase not tightly coupled to the speed.

At highway speeds, 65 mph, it took nearly 18-19 minutes in 88 (F) to reach a stable operating temperature in the 135-140 (F) range. Increasing speed to 70 mph brings it up a couple of degrees but this seems to be a stable temperature for Amsoil ATF in this limited test environment.

The highest temperature shows up several minutes after coming to a stop, typically an extra degree or two.

Bob Wilson

 

"page 24 in the 2k4 Owners Manual Supplement says Hybrid Transaxle Peplace fluid every 72 months or 96,000 Km's 96K=approx70,000 miles."

cool, thank you. I'll look there. Does it baffle anyone else why this is not mentioned in the maintenance booklet? The one where it lists 5,000 intervals for things, a place to write notes and dates...It IS maintenance, right? Not a word about ANY transaxle/differential/PSD oil! Strange that an expensive gearset/mechanical piece is ignored. Conspiracy theories abound... :blink:

 

I apparently don't have the owner's manual supplement...looked at every page 24 in my glovebox: owner's manual, warranty booklet, maintenance booklet, quick guide...no word on the PSD oil and subsequent change interval. Is your's Canandian? Would that be different than US (just as Europe/Japan are)?

Still seems "wrong" that such an expensive item (the actual PSD and transaxle innards) would not have SOME indication of when to replace the lubricant...it can't be bad to change...nor does it last forever. Toyota certainly doesn't want u to NOT change it after X amount of miles, right? Longevity, quality of cars, etc. would be in jeopardy.

Next up, to my service guy at Toyota...but I'm not holding my breath for him knowing either. Much smarter people here.

Cheers,

Curt.