trans. fluid interval

probably need to check the owners manual for sure. when I was a Toyota tech we did a drain and refill every 30K miles. SOme people like to do it more often some dont do it as often. This was in the mid to late 90's so it may have changed since then. IF I remember right that was TOyotas recommendation not jsut our dealerships

Toyota's recommendation is that the transmission fluid does not need to be changed unless you are pulling a trailer or operating the van under extreme conditions a large percentage of the time. The change interval under these circumstances would be 30k miles. Only use Toyota type T-IV transmission fluid.

wag said:

Only use Toyota type T-IV transmission fluid.

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I believe 98-03 Sienna's took dextron and 04+ started taking T-IV.

Nad1370 said:

I believe 98-03 Sienna's took dextron and 04+ started taking T-IV.

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You are correct! Dextron III it is! Sorry Jeff.
I do however find it a bit odd that the 03 & down Highlanders & RX300s with the same drive train use T-IV.

thanks for the info

Thanks for the responses. Wag, you mean the fluid doesn't need to be changed at all under normal driving conditions? Not even at 60 or 90K ? That would be great , just wanted to make sure .

To prolong the life of the trans and ensure proper shifting.

I would change mine every 30K miles.
Really small investment on fluid change ( DIY : 10< dollars at a parts store )

You can now get Dextron III synthetic. I would use this when changed it, change it again in about 5000 miles (unless you were able to flush the old fluid from the converter on the first change) and then forget about changing it again. The synthetic fluid will last the life of the car!
The new type T-IV fluid that Toyota is using is synthetic based, this is why they don't recommend changing it. It doesn't wear out but it does turn very dark (like the old non-synthetic fluids when they need to be changed) within just a few miles. I suspect that the synthetic Dextron will also do this. Synthetic motor oils also exibit this characteristic.