My truck has 170k on it and I have no clue when the time last transmission fluid change was if any at all. I don't currently know what's in my transmission right now and I've got a gallon of the toyota atf type IV but I don't know if it's a good idea to do a drain and fill with it. Don't have time for a flush right now. Anyone know if it's compatible with other brand fluids of dextron iii. Toyota said it would be ok as long as I continue to always use it an nothing else (lol sounds like a toyota gimick).

Since dealers don't stock Dextron (not even VI) here in DC, I would guess they would use Type IV in its place. Yet Toyota still has a part # for III:
Toyota Genuine Parts 00718-ATF00 Dexron III Transmission Fluid - 1 Quart : Amazon.com : Automotive

When you look at a multi vehicle ATF container, and skip down to compatibility for Yotas, you always see Dex and Type IV together.

I would think it would be fine. No bites on CL for it?

Any Dexron II or above labeled product will work. Walmart has Valvoline maxlife ATF for about $17 a gallon and it's synthetic.

Well, after further research it seems like this stuff plays well with others. Just as long as I stick with this fluid for now on if/when I drain it again. I drained and filled with it tonight. Can't really tell much of a difference right now but I'll keep an eye on it.

I'm planning in flushing my transmission, and replacing it with type 4. How's your tranny after all this time?

Bump. Are people using toyota Type IV in their 3rd gen 4runners? I bought 5 quarts of Toyota DexIII but it’s 17$ a quart and I want to do a flush so that would cost me close to 200$. Type IV is much cheaper. Would like to use it if it’s compatible.

Some are using it but the majority recommend against and to stick with a Dex3 compatible. The transmission wasn't designed with ultra light oil weight in mind, that fluid has come about from the necessity of increasing fuel economy and new transmissions are built with the LV fluid in mind. It's just an unknown with only anecdotal evidence to claim one way or the other.

Personally, I wouldn't "mix" the new LV/Type IV with anything, it'd need to be a full fluid replacement. That's essentially impossible to DIY without the proper equipment, as the DIY methods require mixing things together in the transmission. But that's a risk you'll have to assess for yourself.

Similarly, DexIII is a standard. Anything labeled as DexIII meets that standard, and that's all the transmission needs. That means the transmission will be fine with Walmart or Amazon fluid. I get the mental hangup though, I can't bring myself to use the SuperTech/Wally-world fluids, but I have no issues (nor do many others here) with using Valvoline ATF. It's what's in my 4runner right now. I think I paid about $20/gallon, or $100 for my full fluid replacement/flush. If money is a concern, you might need to loosen your standards a little and opt to skip on the Toyota branding and go with a cheaper fluid.

Thank you for the detailed reply. I just want to make sure that I have a fluid that’s readily available so that I can use the same fluid every 30k with just drain and fills after I complete this fluid flush. It seems the Toyota dex III is discontinued or limited supply left. I’d really like to stick with Toyota products if I can which is why I’m asking about the type-4. But, if there is nothing in writing from Toyota saying it’s compatible, Ill have to switch to mobile 1 as I’ve only had good experiences with it.

Just don't use toyota WS. Valvoline max is full synth, toyo is not.

We have Technical bulletins saying we never should use T4 fluid as it's not compatible with our transmission.

DEX III or DEX compatible with higher level of DEX fluid would be better. As T4 has been known to have issues with the 3rd gen. Transmissions.

Search the forum for transmission fluids and you see many posts on the subject along with TB I posted on another thread.




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Really good info here.

I have always been told it’s bad to do a full fluid/flush on an older automatic transmission because it could ‘shock’ the system and cause problems. I was told it was best to do small drain and fills to ease it in there.

Transmission is one of the last fluids I haven’t changed on the runner I recently bought. Will have to run some searches here and look into full flush vs slow drain and replace

Do some more reading, there are a Lot of different theories on fluid flushes. The Main positions are that the transmission was already going and had old/long unchanged fluid with a lot of the friction material suspended that allowed it to continue working and a flush removes that suspended friction material. Next is that in the process of flushing, "crud" can be shifted into sensitive places (though, in reality, that can happen anytime).

If you're paranoid and don't know if the fluid has ever been changed, maybe take a stepped approach. Start with the dipstick for a quick smell and color test. If you can't decide from there, then drop the line to the radiator and take a look at the fluid that comes out there. If it's Very dark and/or burnt smelling you get to decide between just running it and planning on paying for a replacement when it's needed or taking a chance and replacing the fluid (either in a drain and fill or full flush ~ I don't believe there's really any difference). That could mean replacing the transmission right away, or it could mean you never have any issues at all with the transmission.

But do your research. There's a lot of good info out there, both on this site and off (I like bobistheoilguy.com for fluid info too). Ultimately it's a personal decision based on your level of risk assessment.

Many ways to look at this. Basically clean fluid is lubricating fluid. The filter screen can plug up and the magnets get covered in fine paste. I exchange mine at least every 100k miles.

I personally would not use T4 or Toyota WS but as like Brian says. A pile of information out there. Search around and do what's best for you.


I subscribe to the theory that the damage could already occurred. Especially if an issue is already present in the transmission. Exchanged Fluid in a 3rd gen at 215k. My camry at 160k. I will do my 01 Sport at 230k. Just as examples.

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ok so i just picked up 15 bottles of mobile 1 synthetic atf. i will be returning the 5 expensive bottles of toyota dex III. The mobile 1 mentions dex IIIG and dex IIIH i believe. its not just dex III like our manual states. this stuff should work though correct? ive read too many threads and spent too many hours trying to figure this out. i would just like to flush my transmission confidently lol.

As long as the fluid is DEX II , III or higher compatible. Really lots of compatible fluid out there that Isnt super expensive.. Earlier 3rd gen state DEX II the later 3rd Gens state Dex III.