Eventually it will have issues, its just whether or not you want to wait for it to start having issues before you get it looked at or if you are proactive and want to try and prevent future issues. The problem with waiting is that it might start acting funny on a road trip many miles from home.

When I had my timing belt done at the dealer, I asked them to drain and fill the trans fluid. '07 with 180K miles. They said they don't recommend it and wouldn't do it. It shifts ok, but I find that odd.

I have a second one now with 96K miles. The higher mileage one shifts OK, but the lower mileage one def. a little more behind the shifts with half the mileage.

I had the Toyota dealer exchange the fluid on my '08 at 100k after wrestling with the same opinions. No regrets and will do it again at 150k. These transmissions are fairly bulletproof as long as fluid levels are adequate but as others have noted, there's no such thing as lifetime fluid.

I would never consider having it flushed by a non-Toyota service shop, at that point, I'd do the fluid exchange that's been heavily documented here in my driveway.

Edit to add: I talked to several Toyota dealers when doing my research and none of them recommended against an exchange. Maybe it was due to the lower mileage, etc.

I just changed mine at 175K. I used this method Easy Peasy transmission fluid exchange V6

Easy and now it shifts better than ever. Also goes into 4H and 4L a lot faster. Your mileage may vary.

lead tech at toyota of dartmouth knew exactly what i want and needed with 140k on my 04. no major issues on the tranny just one rough upshift when engine was really cold and downhill out my driveway. the drain and filled 4 quarts of fluid, around $100. feels smoother and reassuring.

does anyone know if they check the fluid level during the process above? or drain as much as they can and add the same amount? i have 04 v6 btw, i think i have a dipstick.

I see only one person in this thread has sent their fluid in for analysis. Anyone else?

If your 2004 has a V8, it doesn't have a dipstick, if it has a V6 then yes it has a dipstick, either way the dealership should of definitely check the fluid level after them servicing the transmission, if you do have a dipstick you can check the level yourself just to be sure it's at the correct level, but if no dipstick I would call the dealership and ask if they indeed checked the fluid level, it's important that it is filled to the correct level, either too low or overfilled is not good for the correct operation of the transmission, the transmission is sorta like Goldie Locks it should be just right.

Im almost at 145k and still on original fluid. I plan on swapping all fluids at 150 to keep her running nicely as the miles go up. I swapped everything at 80k(besides the tranny) when I first got it and most of the miles have been highway miles on long road trips. No towing

245k miles on my ‘08 SR5 V6 automatic transmission. I bought it at 88k, and have never changed the fluid in those five years. Probably going to to an exchange at 250k and both diffs and transfer case.

I've had my '06 4.7 for a couple of weeks. 197k and transmission fluid never changed. Went to the dealer today to get some washers and asked about a transmission fluid service. $325 and told they service via pressurized flush method. I asked the same question we all wonder about...will it cause issues on a seemingly properly running transmission. They said "no" (duh).

May go ahead and have them do it...i've seen the fluid when i replaced the radiator last weekend. It's the color of coffee, with a translucent film that seems to gel around the perimeter of where it split on the cardboard and on my finger.

Thought about doing it myself through the cooler lines but need to talk myself in to it first.

just an FYI: changing the trans fluid should not have any effect on the 4wd... 4wd is controlled by the transfer case.

& to everyone like "ugly4runner" telling people not to change the fluid at high miles (100k+) & "trust in your 4runner" .. that is not good advice to give or follow. no fluid is lifetime, especially trans fluid. toyota specifically says to change it at 60k if you do any type of hard driving, like towing, off roading, etc etc. even driving in very hilly or mountainous areas in summer temps.

if you want your 4runner to "treat you right" you need to do proactive maintenance & trans fluid drain & fills or exchange is part of that. you dont just drive it until a problem shows up!

i did a full exchange on my 08 at 145k & while it shifted ok, the WS fluid was very dark, & that was with no towing or orfroading, was owned by a soccer mom & probably never went above 65mph. i replaced with maxlife & it shifts noticeably better.

Old Thread, but I'll add my experience.

My 2003 V6 4spd with 249K miles. Had my Transmission flushed at 120k and 230K miles at the dealer ship. Towed a little pickup bed trailer 45 miles once and that was it. No problem as of today and transmission shifts great.

OP noted 60k mile service so that suggests the original owner did a lot of towing. Also everyone has a different driving style so that's a big factor as well.

@mr_plow ,

Okay, first you said...
"There's a high probability you need to replace your ATF at 60,000mi. Definitely at 100,000mi."

then you said...
"It should be treated like engine oil that only gets changed every 50k miles."

I'm not being a smart a**, I swear. But, if I drive kind of hard (50%), should I change my ATF every 50k, 60k or 80k?
Thanks.

Almost 293,000 now and still on original WS. I did add shudder fix a few months ago as I had a 40-50mph shudder when cold, but otherwise still shifts perfectly. I worked at a Toyota dealer for over a decade, had a customer with 320,000 on 03 v8 and he was still running original WS and never had a timing belt service. Maybe it's just luck or maybe that's why we all love our 4runners. Considering I can find a sub 150k trans for $300-500 I'm not worried about it. Being that cheap and plentiful says a lot!

Disclaimer: I didn't read every single reply in all 16 pages.

Last week I changed out the transmission fluid on my 2008 V8 4x4 Limited (sealed transmission, WS "lifetime" atf)

History of truck: I bought it in October 2018 with 99k on it. One owner truck with every single service done at the dealer. I downloaded the service history from Toyota...every oil change, every bulb change, the exhaust manifolds, timing belt, etc are documented.

Severe duty maintenance schedule says to change transmission fluid at 60k. Since this truck was a garage queen, the previous owner followed the regular maintenance schedule.

It had 123k on it when I changed the atf. It never towed until I bought it. I've made 6 trips towing with it, 300 miles total each time. I tow two snowmobiles in a 16' enclosed trailer.

Here are pictures of the fluid that came out compared to what it looked like when I checked the level when it got to temp (and had to drain some from the overflow). The old fluid didn't smell burnt, but it was pretty nasty. I didn't think of sending a sample in until later that night...all the old fluid was in the waste bin at that point.

A couple things to note:

1) Yes, there is a filter you can easily change once the pan is dropped.
2) There will be some fluid left in the pan once you drain it, but not enough that it will dump on you when you remove the pan (like a GMC K-series will).
3) On a V8 with the aux transmission cooler, the outlet from the cooler is the top hose fitting.
4) I found WS fluid to be cheapest through Amazon.
5) Replacing the fluid via a cooler line is much easier to do if you have a helper who can start/stop the vehicle for you.

I've done a simple fluid exchange using a cooler line on many vehicles with 100k+ miles on them and had no issues.


Edited to add: I bought 16 quarts of new WS fluid. I used 14 by the time I was done. I probably could have stopped at 13, but I'm weird like that.

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