120k mi on original transmission fluid - what now?

Bought my 15 Tacoma 4WD Automatic at 50k mi. Now sitting at 121k mi with a 1.5k mi road trip coming up on Monday. I'm the second owner, and the transmission fluid has never been changed to my knowledge. I did add some Lubegaurd Platinum at 90k mi because I think I started to notice some differences in shifts, but by now I've grown accustomed to it, and I definitely wouldn't say my transmission is having any "major issues" (no hard shifts or slips that I can feel, still idles forwards).

All that being said, what should I do, if anything, regarding the 120k mi transmission fluid? I think a full flush is definitely out of question, but should I even attempt a drain and fill at this point, or just leave it alone entirely.

If I leave it alone entirely - do you just wait for the transmission to fail entirely and hope it takes many many years before it does?

*****
UPDATE for new readers: I ended up doing a pan drop drain and fill and replaced the transmission filter with a new one for good measure. Ended up putting in about 5 quarts of Valvoline MaxLife ATF - only that much because I refilled improperly twice (accidently drained from the drain plug the first time, and didn't have the truck running when checking the overflow the second time). See my update posts in this thread for more details.

 

You speak with knowledge, you know what to do grasshopper? Just do it!

 

I replaced fluid @ 80,000 and am glad I did. Preventive maintenance. If that was my truck, I would definitely do a couple drain and fills. Frankly, I would drop the pan, clean magnets, replace filter & gasket and add all new fluid.

 

Watch this video.

https://www.youtube.com/watch?v=o690DovjDAc

I changed mine at 120k for the first time as well, and of course drop the pan and clean magnets.... 0 problems, There is absolutely no reason to wait for your transmission to fail

 

I've never seen any evidence that changing it prolongs transmission life. I've been driving 50 years and have never changed the ATF on any vehicle I've ever owned. That's several million trouble free miles. Currently at almost 700,000 combined miles sitting on the driveway including 253,000 on my Tacoma. All with the factory fluid in them.

In fact, I don't know anyone who has ever changed their ATF. Certainly no one in my family, nor on my wife's side. None of us have ever had any issues.

The guys at the local transmission shop tell me the same. They claim that if you start at 30,000 miles and change it every 30,000 miles, you'll see MARGINALLY longer transmission life. You might get an extra 30,000 miles out of it, but you'll spend more having it serviced than it will cost you to have it rebuilt.

Some transmissions are good for 150,000 miles, some 300,000-400,000 and changing the fluid at any interval doesn't significantly change that. The Tacoma transmission is typically good for 300,000-400,000.

 

Yes definitely don’t change it, just run that tranny until it fails. Same with all the other fluids, just run em til they fail. You’ll save lots of $$$ and time. Great idea, don’t know why I never thought of it.

 

Jokes on you, I save thousands every year by never replacing my blinker fluid!

 

Mine got a drain/fill/clean magnet and replace filter etc at about 135K. No issues before, just figured cheap insurance. Still moving right along at 145K

 

As long as you are using synthetic blinker fluid you are good indefinitely.

 

If you never use your blinkers, you never need to add fluid.

There. That's a thing you know now.

 

Different vehicle, but I was moving my daughter's 2014 Corolla with the CVT and 230,000 miles the other day, and thought it felt like it took a second longer than it should have to engage and move.
I watched some youtube videos and dropped the pan, cleaned the magnets, replaced the filter and gasket and added back the appropriate fluid. It doesn't have a dipstick so the recommendation is to capture what drains out, add that amount plus a half quart, start the car, run it through 'the gears' at idle a few times, wait for it to get to about 104F (infrared pyrometer on the pan and surrounding housing), then remove the plug and let the excess drain out, while running.
There's a small level tube in there that sets the level.
It's noticeably smoother now and I only replaced about 3 quarts. I was also happy to see that the magnets weren't too smudged up and overall the fluid didn't look too bad.
It wasn't a bad job and gave me some peace of mind.
I think it's also think it's a good way to verify your fluid level.
My Taco is a manual so I've never had that concern with my truck.

 

I agree some do live,some live a long time but just like your motor oil.Why not change it.
It’s cheap and that’s really horrible advise.

 

Just drive it and replace when it goes out. I bet you get another 300K out of it, if the frame last that long. I had 325K on the 4Runner when it was sold to a business as a delivery vehicle. Good luck with your truck.

 

well shit. Working as a dealer tech all 30 of us in the shop do trans fluid at 40k as it’s called for by the engineers/manufacturer. To easily and cheaply change out old fluid that suspends debris, discolors, and burns. on a transmission that by design is serviceable given the presence of a dipstick, plugs, filter, pan, gasket, and magnets to clean.

I guess we’re all wrong.

 

Drop pan, replace strainer, clean magnets and a few drain/fills. Mine was at 160K, never touched and I have the factory tow package with trans cooler. See the progression below.

Tranny still performing great & just broke 200K.

https://www.tacomaworld.com/threads...e-2nd-gen-transmission-pan-and-filter.726329/

 

Transmission fluid degrades with temperature. The hotter it gets the shorter the eventual life. For rough numbers, infinite life is below 170F, imminent failure is above 300F. Not exact science, but I'm sure you get the idea. So the question comes down to how many miles has your transmission operated at what temperatures? Pretty impossible to answer accurately. If you monitor your T/C temp you will routinely see it around 200F or more if lugging hills and such. So being above 170F is typical fact of life, hence the fluid is degrading at some rate. Just where it is unknown without running an analysis of your fluid. At 120K miles you should either be changing your fluid, or getting an analysis to prove you don't have to. Dumbing down the road is probably not what you want to do. If you decide to change fluid, search for threads on Valvoline ATF by Gearcruncher to understand why one of our resident tranny experts very much prefers it over the OEM ATF.

 

Granted I have a manual, but I replace my gear oil every 50k miles.

 

I originally did a pan dump at 19k and glad I did. I was 3/4 qt. low and in cold weather the tranny would have a slight slipping before it warmed up. This has been reported a number of times on here and it’s due to if you had a tranny cooler or not. The tranny cooler takes an extra qt. Factory filling confusion? Probably!

 

I flushed the fluid at 89,000 miles. I first dropped the pan, checked the magnets and then filled it up then did the flush through the tranny cooler fluid lines. I switched over from the WS Fluid to MaxLife. It has been outstanding, I’ve done a pan drop added fluids (MaxLife and Lubeguard platinum) and all is well. I say start with a pan drop, check the magnets see how much metal is on them, if not much, do a flush after the pan drop. I also say switch to MaxLife. You can also get the strainer/filter off of rock auto and the kit has a rubber pan gasket, https://www.rockauto.com/en/moreinfo.php?pk=4768797&cc=3310144&pt=8600&jsn=837

 

Dropped and cleaned the pan, and replaced the filter using NAPA kit p/n ATP 17061. There was a small amount of sludge on the magnets but nothing that looked excessive, especially considering this might have been the first pan drop since leaving the factory. Currently at 126k miles. The fluid has the consistency of water, but I read online that might just be normal for ATF? Will be filling her back up with Valvoline MaxLife and report back on results!