2006 V8 225k miles - transmission fluid never serviced
I removed the trans feed line when i replaced the radiator back at 198k and inspected the fluid. It was a dark grey color. It was thin, not thick. But there was no red tint/tone to it at all. That's what makes me think it has never been changed. I've had the truck since 197k.

well, i was prepping for this DYI fluid change for the transmission: ATF Exchange (using the cooling line)

I called the dealer to put an order in for the the WS fluid (14 quarts) and washers. I asked them to transfer me to the service dept so i could just see what their price and methods were for a flush. I told him what i was going to do and he said if it were him, he wouldn't do either the dealer flush OR the DIY method used above. His logic seemed to be that if it has never been changed there are chances of messing something up, even with a simply manual flush like i was going to do He said if it hasn't been changed/flushed regularly from day one (every 70k he said) then issues could arise doping it so late in the game for the first time.

I had never heard that before...i only hear that when people talk about doing a pressurized flush. It's hard to get my head around his explanation, but he said the additives in the new oil would/could cause the issues(?).



thoughts?

Do it gradually. Buy 10/12 quarts and do a drain and refill once a week for 4 weeks. When I drain mine about 3-1/2 quarts come out. Then in a year do another drain and refill and every year thereafter. Or every six months, whichever.

You'll find a range of opinions but, objectively, every fluid degrades over
time/usage and WS is no different.

Are you experiencing problems or being proactive? I would ONLY consider an exchange, NEVER a flush - no matter the mileage. Toyota did an exchange at 100k miles on mine and I plan to do it every 50k miles as long as I own the truck.

The theory you're referencing is that the fresh detergents/additives may dislodge deposits that have formed over hundreds of thousands of miles causing new issues. My thinking is, if an exchange causes a failure, the failure was always going to happen and fresh fluid only accelerated the failure. So I'd do it but you have to make that call.

Search around, lots of thoughts on the topic. If you DO wind up exchanging, post back with the results/thoughts - it may help others in the same boat.

This is a great middle ground. I do this once per year on our Honda Odyssey which apparently has one of the most fragile transmissions ever made and have had great results.

Wow. Wayyyy over due. Dealer may have just saved your 4Runner.

I personally wouldn't change it with that much milage. But rdruss gradual change sounds like a safer option if you must.

FF to 4:00
How to make your Toyota Last Over 300k Miles without Major Repairs - YouTube

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being proactive, no issues. I don't tow, the PO didn't tow. BUT...i imagine towing in the future...miata/trailer or a potential camper.

I removed the trans feed line when i replaced the radiator back at 198k and it was a mid grey color. It was thin, not thick. But there was no red tint/tone to it at all.

So just drain what's in the pan? Should transmission be warm before draining (get more out). I thought the pan only held 2 quarts when cold. What about dropping the pan to clean off the metal filter?

Hot or cold, doesn't matter, ATF is low viscosity. I wouldn't worry about filter, it's just a screen. No, pan holds 3+ qts.

Too much fear mongering here. I bought a 07 sport with deferred maintenance, ATF never changed. I changed my ATF at 222,000 miles, added a tranny cooler and swapped the radiator all at the same time. I pull a 4,000 Lbs boat. I did the full fluid exchange using the cooler lines to pump out 2qts at a time, I did not drop the pan. What You need to consider is the effect of 100% new synthetic ATF, I used Amsoil, on the dirty transmission. The detergents will clean internal parts which may free up dirt and potentially clog small passages and effect shifting. What I consider an absolute must is to add an inline Magnefine filter just before the radiator cooler. This will capture every bit of crap that leaves the tranny so it cannot recirculate in the transmission. My truck shifts strong just like new. Also, what breaks down ATF is heat. Keep the fluid between 140-180*F and the syn fluid will easily last 200,000 or 100,000 for non-syn fluid.
At this point, if you dont change it now the tranny will fail in the next 100,000 miles. That dirty crap will clog your passages. But 200k on a toyota is nothing. Change it now. If you do 2qts every 2 weeks, you are only diluting the very dirty ATF and not improving a thing. The best you can achieve after 10qts (5 drain and fills) over time is 60% new fluid est. why bother? If you dont add a cooler, use Synthetic ATF to buy more time at higher heat.
The cooler I prefer is the B&M 70264 with 3/8” ports mounted on the AC condenser. This allows the fan to draw air across it and alway provide airflow even when standing in rrush hour traffic in the summer. Its the most efficient setup. I also added a derale bypass so it does not overcool the ATF in cold winters.

Magnefine Inline Transmission Power Steering Filters

Attached Images

   

thanks for the detailed info and pics. The V8 has a trans cooler. The Magnefine filter may be a good idea if i decide to do a DIY full fluid change. I hesitate to throw a different ATF in there, esp if i'm not experiencing any issues. I do have an OBD scanner that shows operating temp for the trans are in the 170s. What i may do is drain out the pain, refill with WS and send some off to Blackstone for an analysis.

I bought my 08 V8 @ 161k miles and never had records of it having been changed. I did the full fluid swap with WS fluid @ 162k miles and am now @ 166k. My trans was shifting fine when I got it and is fine now. There is no such thing as a forever fluid. A lifetime fluid assumes breakage will happen.

Changing it out slowly is probably the least risky way but I'm not a believer that changing to new fluid is going to magically break your trans. Agree that the only reason that makes any sense is if it dislodges stuff. I read up on that a lot before making my decision and I didn't find any real data that suggests that. I believe it is that people usually only think about their trans fluid if the trans starts shifting rough or slipping. Then they ask a shop to flush it and it breaks soon after. Person says it was better before the flush and blames the flush.

If it was mine, I'd probably just swap all the fluid as you wanted. I'd be afraid and I'd be babying it/tracking temps for a while after. I did that on mine too. Now I don't think about it ever and will be towing with it sooner than later.

you did the fluid change yourself or you got it flushed by the dealer.

Toyota Master Diagnostic Technician says don't change it with high milage, so I would err on the side of caution.

of course, today i went to another dealer (different than the one who said "don't do it if i were you") to pick up some WS and swung by the service dept and they were all gun ho about doing the dealer flush.

Because they want your cash - what do they care if it fouls up your truck? Not that it necessarily will - I lean toward doing it - just pointing out that their motivations may be different than yours.

Could have missed one, but I’ve been on this board since 2014 and can’t recall any “damn I shouldn’t have exchanged* my ATF” posts. Does anyone else? The ones I’ve seen have all been improvements with new fluid. And FWIW, I did mine at 114K and again at 218K w/ no issues using the cooling line DIY method. Still shifts great at 236K.

* Not a pressurized flush!

P.S. I just noticed you said you called the dealer about WS and washers. Take a look at parts.toyota.com - it’s a Toyota site and you can usually get much better prices than the parts counter with either free pickup at the dealer or often free shipping. Last time my WS was ~$8 a qt.