I have an 04 Sport V8 AWD. I just turned 16k miles on it. I changed all my fluids to Mobil 1. I also like to change my trans fluid at this time also. My dealer is telling me, along with the regional parts director for Toyota, not to change my fluid. He said it is designed for lifetime. He said if I do change it, its like 10.00 bucks a qt. I just cant see how they can make a fluid last that long. When I turn 90k and my trans is fried, I wonder what they will say then. Anybody have any thoughts?

I got the 100,000 mile warranty, so if it fries at 90,000 kudos for me!!!

Look at this link, a few places throughout the .pdf files it says to visually inspect it if under heavy conditions. I think around 90,000 it says to change it, but I didn't review all of the files. My dealer gave me a hard copy printed (not computer printed) book of the .pdf the book.

Toyota Service and Maintenance

only thing i can find is at 60k then every 30k, you replace the limited slip diff oil.

everything else is on a as needed basis based on visual inspection of the oil during each checkup.

personally, i would go on the either the 30k, then every 30k

or the 60k then every 30k schedule.

but thats just my opinion.

I just had all of my fluids flushed and changed. Engine oil, tranny, transfer case, and both diffs. I will flush everything again at 35-40K miles.

I have 15,250 miles and after flushing the shift points are tighter and the gear whine up front has subsided.

For 2004 model years Toyota went with a different type of fluid. They are saying it is life long. We dont even have a dipstick to check it with! You have to get underneath and check it like you would on a manual transmission.

Son of a gun! That must have been a shock looking for it and finding out that it doesn't have one!!

My 2004 manual states that for regular service you don't need to change the fluid and for severe service change it a 60K mile interval. Since the powertrain warranty will be up at 60K miles I figured I would change mine at 45K miles so if there were any problems it would hopefully show up before my 60K mile warranty was up. I also plan on trading at 90K miles so it would be half way through my planned ownership.

I would check the owners manual on the type of fluid the AutoTrans uses. My '03 uses Type IV, which is a Toyota synthetic.
As far as I know, they are still using Type IV in the '04. And, yes the Type IV is much more expensive that the older fluid. You can still drop the pan on the newer units, and change the filter if needed, but with no filler tube, it has to be refilled thru a sight plug in the side like a standard. Real convenient.

NO my 2004 owners manual states that my 5speed has ATF WS type automatic transmission fluid. The Type IV is still used in the 4speed transmission. The owners manual also states that the ATF WS should not be changed unless you meet the severe service criteria and at the 60K mile service interval and then you must us the WS fluid. If type IV is expensive I wonder what the WS costs. Also if I had a 2003 4runner with the 5 speed transmission and I changed the fluid I think I would go for a complete exchange using the WS fluid since it is the latest and greatest fluid. I would also be concerned that the Toyota dealer used the right fluid when they did my transmission service since the 2003's used type IV and the 2004's use the WS. The way most of these dealers operate I would have to see the fluid before they put it in the transmission. I would be concerned about how this stuff would mix Based on this and the fact that I will not tow or haul and I will trade at 90K miles I might be temped to not do anything. Any one know anything about this WS transmission fluid???

Got this from one of the best Toyota parts guys in the country.

"Toyota has not published any kind of information that I am aware of that states what the difference in the fluids is. They should not be mixed. They do say" "WS FLUID IS A WORLD STANDARD(WS) FLUID THAT IS NOT INTERCHANGABLE WITH ANY OTHER FLUID AND AT THIS TIME THERE IS NO EQUIVALENT FLUID. DUE TO REDUCED VISCOSITY, IF A VEHICLE CALLING FOR WS FLUID IS FILLED WITH ANYTHING ELSE, THE VEHICLE MIGHT NOT START OFF AT EXTREMELY LOW TEMPREATURES UNTIL THE FLUID IS WARMED UP. THE VEHICLE MIGHT ALSO EXIBIT UNFAVORABLE SHIFT CHARACTERISTICS."

Toyota supplied T4 (what I stock) lists for $4.15 a quart. WS is packaged in a 4 liter steel (like a Coleman white gas can) can and lists for $40.59 ($9.60 a quart according to my high school math )

i wonder if this new WS fluid helps with the transmission shifting better compared to the old transmissions holding the lower gears until its warmed up?

honestly i havent even notice it holding a lower gear like the 3rd gens do anymore. i guess that is the price you pay for the little things. but man thats $$$ fluid compared to the old days.

It wasnt the fluid thats holds the gear changes. It is a solenoid that is tied into the coolant temp sensor.

Pitbull

I thought I read someone saying the coolant was changed to superlong life and last 100k, does it say anything in your manual about that.

Your right super long life and don't change until 100K miles.

It does say that... However... Are you going to let your thermostat go that long? You normally change the coolant when you change the thermostat. Also when you do the timing belt you also change the water pump, which in turn means you need to change the fluid. Just my thoughts.