ATF Fluid drain and fill

I wanted to see if anyone has advice on weather or not I should do a drain and fill on my automatic transmission. I am at close to 250k miles, and things seem fine with it. The previous (and only prior) owner kept up with engine oil changed regularly, but I don't know if/when he had ATF drained and filled.
It seems that some mechanics don't recommend doing that drain and fill if you don't know the history. Apparently suspended particles can keep the transmission working well when it otherwise wouldn't? Not sure if I agree but I wanted to see what other people's experiences were, good or bad.

 

This has been gone over before, but that is a myth about not changing the oil.
You change the oil for everything else, it breaks down and becomes contaminated, why wouldn't you do the same for your transmission?
I guess the theory is the new fluid breaks down the gunk holding your old transmission together, but that seems like a time bomb waiting to happen.
If he kept up on the engine oil I bet he did the same for the transmission.

You are probably going to get a bazillion different opinions on this....

 

I’d check the fluid first. I checked mine at 170k miles and it was dark brown (new ATF fluid is dark pink). Clearly had never been changed before I bought the truck. I noticed a small improvement in shifting.

I think the real risk of dislodging particulates is with a full ATF flush on these older trucks, and not just a drain and fill. Draining the fluid might bring some stuff out of the drain pan, but as far as I know it won’t dislodge those particulates that are in the transmission itself.

 

https://www.tacomaworld.com/threads/transmission-advice.832686/#post-29841118

 

I have 265,000 on my truck. I've done 3 drain and fills over the past 20 months. Mine was original fluid most likely. I have also noticed smoother shifting definitely better color and no new problems. I used valvoline Maxlife ATF and replace what comes outta the pan usually close to 2 quarts a session. I use 2 graduated pitchers to compare and keep the fluid level the same. 2 more times stretched out a few miles and will be all new. I read some stats about Aisin A340 having a service life of 350k. Hopefully I will get more outta mine.

 

https://www.tacomaworld.com/threads/high-mileage-2002-prerunner-diff-oil-trans.833159/#post-29857418

 

if you are mechanically inclined I would recommend dropping the trans pan. You can clean the 3 magnets, the inside of the pan and replace the mesh screen. Don’t bend the pan when removing it, and follow the instructions when using the Toyota fipg. Then 2 more drain and refills about 3-4 months apart. Shit install a trans cooler too.

 

Thanks everyone for your response. It seems unanimous so far that a drain and fill will not set off an avalanche of problems. To me the only part of the argument against changing the fluids is the fact that there are potentially detergent additives that could loosen buildups dislodging stuff that could clog things up. If the ATF fluid is detergent free, then I can't imagine that argument holding up.

The question is, has anyone heard of a "drain and fill" mucking up one of these transmissions? One that was previously working fine(ish)...

 

I may clean the magnets next time, just because I don't have time to do it now, unless you think I should wait until I have more time and do a magnet clean the first time.

 

nah, a drain & refill will suffice

 

If you're going to do the pan drop, do it right. Arm yourself with the following -

1. Makes pan removal much easier and can help to avoid tweaking the pan -

$25 Lisle 50210 Gasket Separator

https://www.amazon.com/Lisle-50210-Gasket-Separator/dp/B09NMH7TY4

2. Scraper to remove original FIPG -

$11 FOSHIO Plastic Razor Blade Scraper Include 2PCS Scraper Tool and 100PCS Blades for Gasket Remover, Labels Decal and Adhesive Remover for Windows and Glass,Blue

https://www.amazon.com/gp/product/B076BBW1WM

3. Makes removal of any leftover FIPG material a quick and easy job, they wont last forever but it'll do the job without marring the surface.

$13 Supkeyer 6Pcs Stainless Steel Bore Brush Bristles Wire Brush Wire Tube Cleaning Brush Washing Polishing Tools with 1/4" Hex Shank Handle for Power Drill Cleaning Impact Driver (Copper)

https://www.amazon.com/gp/product/B09YQC3568

4. Toyota Orange FIPG (00295-01281)

 

Honestly imo dropping the pan is easy and necessary

 

If you're going to drop the pan, let the FIPG cure before refilling.

 

I apologize ahead of time about this contested high mileage 1st T fluid topic
Just putting this out there

I discussed this “never been changed 250k, owner wants T flush” with old mechanic
he explains…..
ATF is a detergent, cherry red
The reason why red turns to black, is the fluid picks up all the automatic clutch(s) material
So the 250k tranny, with black fluid works fine.
Replace black fluid with new cherry red,
The clutches will start slipping, bc the old black fluid actually provides “floating”clutch material to make T work properly
In some cases, the cherry red fluid is more slippery, causing clutch issues/slipping

he also stated that a big variable is manufacturer.

he advised, if you feel you have to change black fluid, try a little at a time
I.E. don’t shock the system

I’m pretty sure I saw complete flush done and our trannys hold close to 5 gallons of T fluid(I couldn’t believe it)
Cheers

 

IIRC, the FSM for '03 says there is a 10 qt capacity for the A340F

https://www.tacomaworld.com/threads/how-much-fluid-does-an-empty-a340f-take.805583/#post-28884072


I believe you have to add two more qts for TC.......

a43d auto rwd's use ~ 9.5qts including TC


I would not run old fluid in old lines......both are competing to destroy the other

In this age there are numerous friction modifiers and slip conditioners to deal with the consequences

running old fluids is number one reason for seals failing all around the vehicle

 

Let’s ask somebody who knows for sure

@gearcruncher

 

A stiff putty knife works great as well. Wire wheels are great at getting the fipg off the lip of the pan where the scraper can't get.

 

For the transmission, it's oranges. Merry Christmas.

 

The more you know

 

The easier it gets…