Transmission fluid - what to use and how often?

I just changed the oil on my 2021 4WD Tundra. 59,000 miles. I'm thinking about changing transmission fluid in the next few months but was wondering how often does it really need changing? Most of my miles are in a rural area and I very rarely tow a trailer.

Also, is Toyota transmission fluid absolutely necessary or are there others out there that perform just as well?

 

I’m no pro - literally just did my first one 10 minutes ago. I believe Toyota recommends 60k for a drain and fill.

As for the fluid, from the sounds of it the overwhelming majority of people say put Toyota WS fluid back in. I tend to agree just on the basis that when you drain and fill you’re only getting a few quarts out and who knows how different brands play together when they are mixed. Hope this helps

 

WS ATF, drain and fill every 30k miles.

 

Toyota WS, Idemitsu TLS LV and AISIN work well. I'd opt for 30k fluid changes. If you have a cooler which would be advisable you can almost do a complete fluid change instead of a few quarts here and there.
Some have good luck with the global fluids which are based on dex 6.

 

x3

WS ATF and D & F every 30k

 

I do my own D&F every 30k-ish miles.

I installed the cooler early on.

I have used Valvoline Maxlife ATF from the get-go.

WS=WS

I'm at 125k miles.

 

Good advice here. Thanks to all. When you say "drain and fill", are you just talking about draining the fluid from the drain plug at the pan? Not removing pan, cleaning the magnet and filter and replacing pan with new gasket? My dealership wants $350 to "drain and fill" but they suck the oil out and drain it. Seems like a lot for not taking the pan off.

 

Ive done it 4 times now at 135k. Maxlife for all changes

 

Do you just drain what you can from the plug in the pan and replace that volume?

 

No. After draining, you refill with slightly more than what came out. There is a procedure that involves getting the fluid up to temp and opening the check plug and letting the extra come out until it’s just a dribble. Then it’s full. If it’s low, and you didn’t know it and just put the same amount that came out back in, it would be low after your D&F.

 

I'm at 74K and to my knowledge mine has never been changed. I am the second owner. I am wanting to do it but nervous. I am not nervous about doing the work. I have just always heard if you change it after a certain amount of mileage, I may be doing more harm than good. I am open to opinions on that.

 

Drain and fill is “safe”

trans flush is not “safe”



if you can change oil. You can d&f a Toyota trans. It’s easier.

 

this needs to be repeated in every d&f thread



it sounds complicated

it’s not

I can do it

 

Thank you! I have never been a fan of a trans flush no matter how many miles. The fluid still looks good, But I would like to start changing regularly regardless. Thank you for the info!

 

And don’t clutch your pearls over the correct “temp”. When you check it

EVERY time I’ve done mine it took 5 minutes to get to that temp

I don’t even bother with the temperature thing

warm a few minutes . Check valve thing

wait for trickle

close it



ftr. 3.8 qts drain out in 10minutes

I add a gallon of maxlife.

I get rid of the excess during the check valve process

 

Sorry for my ignorance, but I have no idea about this. Is there a post that explains a bit more or can you elaborate?

 

https://www.youtube.com/watch?v=NUAuGmDGntY

 

It’s even listed as a “temperature range” in the procedure description. When warm, the fluid expands some and flows easier. Those two things make it give you the proper level when coupling the check plug. Doesn’t have to be exactly 115° F. Has to be in a range around 99°-111° or so IIRC.

How about a video
https://youtu.be/NUAuGmDGntY?si=4c5hCPIS0caOkv8G

 

Basically. Get a pile of the crush washers from the dealer, same size for drain and check plug. 24mm socket opens up the fill plug, no gasket on that one.

I wouldnt stress too much on the fluid level, get close and you’re likely good. I have a trans temp on the scan guage so it makes the checking procedure a ton easier

 

If you look in the specifications section of your owner’s manual, the automatic transmission fluid is the only case where a Toyota name brand fluid is specified, but “or equivalent” is not an option. Lots of people do just fine with many other brands of fluid, so just something to consider in your research

 

Toyota WS fluid. Every 60k. If you tow alot 30k.

 

I did drain, remove pan, change filter and clean magnets at 30k. Did another drain and fill when I installed cooler at about 50k, plan on just drain and fills every 30k from now on. Procedure pretty easy, I have scan gauge installed.

 

FWIW, I pulled a sample of ATF to send to Blackstone at 180k miles or so. 30k mile intervals since I bought it new. The oil/additives looked good but it was still fairly dirty. They recommended a couple extra D&F’s over the next 30k interval simply to clean it up, not because the oil was degraded. Which makes sense since there isn’t a serviceable filter to remove wear metals like an Allison 1000. I used strictly Toyota WS from the dealership or Aisin WS. The transmission has lived behind a Whipple for the last year and a half hauling and towing regularly.

 

When I installed my cooler/filter, I replaced with all the fluid with Amsoil blue cap ATF and it’s been fantastic, shifts like butter.

 

I just did mine over the weekend at 100K mi. Fluid looked good. 4 qts. came out. I replaced with 4.5 qts. Let the transmission get up to temp opened the check plug and a .5 qt. drained out. I plan on doing it again this coming weekend and then every 50K. I used AISIN WS.

 

Dirty with what? Torque converter wear materials?

 

Clutch material, which is pretty normal and expected over time.

The the OP, like others have stated, it's an easy procedure to just drain and fill. Based on your usage every 30k is fine. Heck even 60k like Toyota says if you want, but it's cheap insurance to do it sooner.

I did a full fluid "flush" about 12k miles ago when my truck was at 94k miles. It was a DIY full fluid exchange not using an external machine. Basically just a ton of drain and fills all at once using the cooler lines to drain the pan. I used AISIN WS ATF. The transmission is made by AISIN, so it was pretty obvious that I was okay to run their fluid. It's also half the price of the Toyota branded one, less than $7 per quart: https://tinyurl.com/AISIN-WS-Fluid

I used 14 quarts to do my full flush, and I'll just do drain and fills from here on out.

 

Normal clutch and steel material. And dirty is relative… dirtier than new fluid, but not dirty enough to cause an issue. I’ll see if I can dig up the report, but it should illustrate how normal wear materials become suspend in the oil and how important changing fluid is in a “sealed” transmission.

 

Just curious if it was actually getting dirty. Like from environmental contaminants. If it was that dirty in a short amount of time with torque converter wear byproducts, I would worry for longevity of the transmission.