When to Change Automatic Transmission fluid?
 

I have almost 20K miles on my tC, so I swing by the dealership to get 4 quarts of auto tranny fluid (type IV) for a future fluid change.

However, I noticed on the tranny dipstick, it says the auto tranny fluid doesn't needs to be changed (under normal driving conditions).. and I couldn't find anything in the owners manual about this.

Surely the tranny fluid can't last FOREVER can it? Is the tC's tranny THAT durable, or is the ATF fluid THAT good? Both? Neither?

And what the HECK do you use to unscrew the drain bolt with? I'm guessing Toyota purposefully used that hexagon hole to deter less-mechanically inclined people from messing with the ATF?

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You can usually tell the tranny fluids life by the color. open the new bottle and compare the color to the fluid in your tranny. If it is darker almost to a brown color it needs to be changed. I suggest getting a tranny flush because if you just drop the pan and let the fluid out you are still missing about half the fluid that gets stored in your torque converter. Usually the OEM Maintenance Guide will tell you to change it at 50,000 but that's if you drive like a granny.

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I change mine once a year, which ends up being about every 16k miles.
Auto in the heat + stop and go traffic is hard on the fluids.

i just changed mine at 33k. you don't have to flush out all the fluid though, just a drain and refill is fine

what did you guys use to unscrew the plug? it's like an inverted bolt hole or something.. i think i've seen a tiny tool like that for electronics, but do they make one that big for cars? i think the size was 19-21mm?

taken from.. you can guess... the Owner's Manual.

Yes, but it doesn't say when you should change it. All I wanted from the owner's manual was a ballpark figure. But it basically says you don't need to change it at all under normal conditions.

Which I find hard to believe. And when I call up the dealership for advice, they say I should bring it in for inspection.. NO WAY!! So here I am seeking advice on these forums..

And yes, I did do several searches, but couldn't find any answers yet.. which is:

1) What's the recommended change interval for ATF, and 2) How do you unscrew that plug? It doesn't appear to be the same as the manual tranny plug pictured in the DIY tutorial.

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gdtc: read my post above. I think my plan is good and works well - it's what I've done in 35 years of driving.
Just having them drain and refill (or you) is good enough - it replaces most of the fluids, and is a lot less of a PITA than a true flush/refill.

Scott

4 quarts are still needed for the drain and refill?

I doubt it. I can't say as I have my mechanic do this service.
You should be able to call a dealer and find out.
If you buy four, the worst problem you will have is an extra bottle or partial bottle.

Scott

Thanks, SiontCya. I'm definitely going to change it. I was just curious as to what Toyota recommended for ATF fluid changes, that's all. I thought it was pretty bold (or is it arrogant?)
that they would recommend never needing to change it..

Yes, I too agree that the drain & refill is sufficient. I have almost 300,000 miles on my old car with just drains & refills. So I'm very skeptical that a flush will do any better for my car's tranny.

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the owner's manual (page 252) lists the "drain & refill" capacity at 3.7 quarts - for automatics.


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Cool.
I think it's fine.
I baby the hell out of my machines, and this has always worked well.
Unless you race or leave it in too long, I do the once a year drain and fill.

Good luck,
Scott

I thought the long life stuff was good for way more than what you guys are talking about?

I figured atleast 50k or possibly 100k

So they say.
I don't believe in keeping fluids in that long.
I've even got an extended warranty to 7/100,000.

Up to you, I don't like keeping fluid that long.

I don't understand why.
They are not just going to put whatever is available, I'm sure they made some good ATF, tested it and labeled it as "Lifetime"
I know life time is not that but ya know

I keep syn oil in the engine for 7k and its still clean.

I'll just check the trans color and level to tell me when its time to change

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As I said, totally up to you.
Let's leave it at that.
My day to day is a lot of stop and go traffic in extreme heat.
That's not good for a tranny or engine.
Don't you think the dealers hope you bring in your car for expensive work after the warranty expires?

make sure u change the fluid not flush. flushing the tranny fluid is not really necessary and manufacturers don't recommend it. notice that the dealers don't really push trans fluid flushes... or at least they shouldn't.

do you guys recommend AMSOIL or Royal Purple

they're almost identical except for the Kinematic Viscosity @ 100°C

Amsoil 6.8 and Royal Purple 7.4 otherwise almost identical

Don't know.
I'm going to try RP this time.
I'll post back when I've done it.