4th gen Tacoma transmission fluid change DIY

[TrustButVerify]

I over heated my transmission when I was off roading. I was only at 5000 miles but decided to change it just in case. The fluid was a bit used but not terrible. I probably could have gone longer on it but once I was in it, I just completed it.

Same for me. Surprising how quickly 4HI roasts the transmission temps. The moment the temp hits 220F, the dash gauge moves up, and it moves up quickly from 220F to 250F. And it stays hot for a long time. Even switching to 4LO, which helps some, kept the fluid temp fairly high for a long time. Not sure if there's any active cooling on this or not, but it doesn't seem to have any.

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[559Taco]

Same for me. Surprising how quickly 4HI roasts the transmission temps. The moment the temp hits 220F, the dash gauge moves up, and it moves up quickly from 220F to 250F. And it stays hot for a long time. Even switching to 4LO, which helps some, kept the fluid temp fairly high for a long time. Not sure if there's any active cooling on this or not, but it doesn't seem to have any.

I finally just ordered an auxiliary transmission cooler to deal with the issue.

 

[Reconsnake]

I am interested in which one you went with, and of course an after install report on its effectiveness, if you would be willing to update us.

 

[559Taco]

I am interested in which one you went with, and of course an after install report on its effectiveness, if you would be willing to update us.

Derale 13740 Hyper Dual-Cool Remote Cooler. I'll let you know how it works after the install.

 

[TacoToni]

I tried doing this today but I didn’t find the internal standpipe. I ended up replacing the same amount of fluid that I removed, which was about 600ml. Any ideas of why I didn’t find the standpipe?

 

[559Taco]

I tried doing this today but I didn’t find the internal standpipe. I ended up replacing the same amount of fluid that I removed, which was about 600ml. Any ideas of why I didn’t find the standpipe?

I'm not sure. That's strange.

 

[TacoToni]

I'm not sure. That's strange.

Do you think it takes a 6mm hex to remove the stand pipe instead of a 5mm? Cause today I had to use a 6mm just to remove the metal plug but you have 5mm listed

 

[TacoToni]

So I did the fluid change and it’s a 6mm hex for both the drain plug and the stand pipe

 

[559Taco]

So I did the fluid change and it’s a 6mm hex for both the drain plug and the stand pipe

Perhaps I thought it was a 5 but it was a 6. I can't remember at this point.

 

[TacoToni]

Perhaps I thought it was a 5 but it was a 6. I can't remember at this point.

all good!

 

[PittPens80]

Can you tell us what the part number of the gasket is for both the to fill plug and the bottom drain plug that is to be used?

Surely you didn't just use the same gaskets.

I'm finding different conflicting information.

One place is telling me both fill and drain plug use the 35178-30010 gasket.

Another place is telling me the drain plug is Drain Plug Gasket: Toyota Part # 35178-30010 (Crush washer); Fill Plug Gasket: Toyota Part # 90301-15004 (Rubber O-ring).
Gasket Part Numbers

Third states:

• Drain Plug Gasket: Toyota Part #90430-12008 (12mm crush washer)
• Fill Plug Gasket: Toyota Part #90430-12008 or #35178-30010 (often used for the fill/check port depending on your exact build and plug type)

So I'm not sure what is correct.

 

[GSPHerder]

Anyone have a guestimate on the actual tranny temp when the OEM gauge shows that the temp is past center/normal?

Most of what I've gathered agrees that around 200 degrees the fluid is being affected

175–200°F (79–93°C)ElevatedCommon during towing or hillsATF begins mild oxidationMonitor temp if towing; consider external cooler

200–220°F (93–104°C)HotHigher-than-ideal tempATF breakdown acceleratesReduce load; stop to cool if needed

220–240°F (104–116°C)Very HotATF is losing viscosityTransmission wear increases rapidlyStop driving; allow cooling

240–260°F (116–127°C)OverheatingDamaging rangeClutch plates glaze; seals hardenService may be required soon

260–280°F (127–138°C)Severe OverheatFailure imminentATF burns; transmission may slipTow vehicle; do not continue

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