transmission/differential fluid

Yup, the "punkin" sits at the bottom/back of the transaxle unit,
lubed by the same 4 or so quarts of fluid as the PSD. There's a
fill/level-check hole on the front of the case. See this for some
more details; which way you'd go at changing it is optional but if
you're an '07, you don't have to worry about it till 50K or so.
.
_H*

 

Or maybe Mr. H is advocating fluid changes more frequently than Toyota suggests... Does Toyota ever recommend changing the transmission fluid?

 

on page 24 of the 2k4 Prius Owners Supplement Manual it say's.. replace the fluid every 72 months or 96,000 Km's. 96,000 km's = approx 60,000 miles.
Edit: same page same recommendation for the 2k3 Prius.

 

Thanks, Frank. I went online to look at the scheduled maintenance for a 2007. At 60K miles it says:

Replace engine oil and oil filter 1
Rotate tires
Replace cabin air filter (if equipped)
Replace engine air filter
Inspect the following:
- Ball joints and dust covers
- Brake lines and hoses
- Brake linings/drums and brake pads/discs 2
- Differential oil
- Drive belts 3
- Drive shaft boots
- Engine coolant 4
- Engine valve clearance
- Exhaust pipes and mountings
- Fuel lines and connections, fuel tank band and fuel tank vapor vent system hoses
- Fuel tank cap gasket
- Radiator, condenser and intercooler
- Steering gear box
- Steering linkage and boots
- Transmission fluid or oil


Additional Maintenance Items for Special Operating Conditions:

Driving While Towing
- Replace front differential oil
- Replace transmission fluid or oil
- Tighten nuts and bolts on chassis
Driving on Dirt Roads or Dusty Roads
- Tighten nuts and bolts on chassis

Applicable Footnotes:
1) Reset the oil replacement reminder (“MAINT REQDâ€) light after replacing engine oil, if vehicle is equipped with this light.
2) Inspect thickness measurement and disc runout.
3) Initial inspection at 60,000 miles/72 months. Inspect every 15,000 miles/18 months thereafter.
4) See Maintenance Definitions (Engine Coolant) for details.

So now Toyota says to inspect the trans/diff oil at 60K and replace it if you've been towing, which they expressly tell you not to do. I'm not saying you shouldn't, I'm just saying Toyota doesn't recommend it.

 

<div class='quotetop'>QUOTE(Bill Merchant @ May 18 2007, 02:45 AM) [snapback]444703[/snapback]</div>

Bill,

Don't believe everything that you read. I changed out my Trans Fluid (Toyota type WS - 2004 Prius) at 61,000 miles and sent a sample of both the used and virgin fluid to a lab for testing. The lab report said that it was in reasonable shape, but was just about used up. As Hobbit said, changing the ATF at 60,000 miles is probably a good idea.

JeffD

 

Oh, right, you guys probably haven't been following the ongoing
thread in the prius_technical_stuff yahoogroup [highly recommended]
about Bob Wilson's oil and tranny fluid testing marathon. Folks
there have concluded that even 50,000 mi on ATF-WS under normal
conditions is pushing it. Bottom line is that Toyota may have
stretched the intervals on some of these fluids, if for no other
reason than it looks like better reliability/hands-off in the
schedule. To their credit, even the shorter intervals that the
owner community has determined are still refreshingly long, esp.
by contrast to fluid change intervals in cars only ten years ago.
This is largely because of improved chemistries. But you still need
to be careful to use the OEM fluids -- the aftermarket for EXACT
equivalents is still very sparse.
.
Data collection is ongoing; that's why I sent off my sample to Bob.
.
The scattered reports of BURNT motor windings in the Classic prius
are also causing increased skepticism of the change interval of the
T-IV fluid in those. Remember, the fluid is in direct contact with
the motor windings, and while it's normally an insulator, time and
distance may start changing that.
.
_H*

 

<div class='quotetop'>QUOTE(hobbit @ May 17 2007, 04:52 PM) [snapback]444505[/snapback]</div>

I'm approaching 50k on my '05 now. Any special gotchas in changing the fluid. Am I better off to have the dealer to it with my next oil change, or do it myself. e.g., how much more would the dealer charge than I would pay for the fluid doing it myself? I've been sticking to the dealer for oil changes, just to simplify warranty issues.

Dave M.

 

about a year ago here on PC we had a big discussion about the PSD fluid and I made a filter adapter and installed a Toyota Torgue Converter filter for a Toyota forklift on my 2K3 Prius and today I changed the filter and the PSD oil as well as dropped the pan and cleaned it out. Not a lot of contaminants on the magnet in the pan or the magnet that I put in the filter adapter. Took a sample and will send it out for analysis next week. It looks clean and red just like the stuff I put in, Type T-4 as I have a case that I bought last year. I'll post the results from the first test and this one so people can see if a filter is a good addition or if it's not needed.

 

<div class='quotetop'>QUOTE(dmckinstry @ May 18 2007, 02:58 PM) [snapback]445081[/snapback]</div>

easy to get out, not so easy to put it back in. DH has a special tool for doing such a job that makes things drastically easier. labor for the job should only run ya in the $40-50 range.

 

On my 04, I've changed the PSD fluid three times now. I've gone into details in older threads, they should still be hiding in the forum here. It helps that at my hobby farm I built an elevated car/truck ramp out of old railway ties. The ramp is extremely strong and although not tall enough to stand under, I can easily sit up under the car. Way easier than jacking it up.

IMHO Toyota has a glaring goof with the drain plugs for the inverter coolant and the PSD fluid drain. A person would naturally think the regular plug is the PSD fluid, when it's actually the coolant drain on the case. Take that plug off, let in a bunch of air, and you're towing your Prius to the dealer to go through the complicated coolant air bleed dance.

It's not very intuitive at all to have a hex head for a fluid drain, though I've noticed Toyota has gone to this design for other models too. My 07 FJ Cruiser uses hex head on the front axle drain AND fill plug. Last month I had a bitch of a time changing the gear oil in that front axle. The transfer case and rear axle was almost too easy.

It's not so hard to refill the PSD if you have some basic equipment, no need to spend a huge pile of money. The WS fluid is a fairly low viscosity, like any modern ATF, so just about any cheap auto parts fluid pump will work. Shouldn't cost more than $20 for such a pump, which includes long hoses for suction and discharge.

I haven't seen the WS fluid in litre bottles up here, but in a 4 litre tin can. That usually costs me $38 Cdn plus GST/PST.

I first dropped the PSD fluid at around 13,000 km, and it came out fairly dark. I should have saved the fluid and had it tested. The magnet had about the same fuzzies as Hobbit's did. When I did it again at around 35,000 km, it came out much cleaner. Last fall at 72,000 km, it came out just as clean as it went in. If I keep the car, I'll let it go past 120,000km before changing it again.