Is draining/refilling automatic transmission fluid important?

How often should I be draining ATF and putting new stuff in there? Just realized my high mileage 2001 tundra probably hasn’t had it done in awhile…

and what ATF do you use? Can I buy it at dealership?
Thanks!

 

Yes it's important. I believe the service manual calls for a drain/fill every 30K miles. It will take 4 quarts for a drain/fill at the pan. The total capacity is something like 13 quarts.

EDIT: As for which fluid, it calls for Dexron 3. So anything with that rating. I also use Valvoline in the blue bottle.

BTW, the power steering also takes Dexron 3. Get a second gallon and do the power steering flush while you're at it.

 

Just don't do a flush if you're not sure of history. Drain and fill isn't a bad idea. I've done a few on my 01. Valvoline Dex/Merc works fine and is cheaper and easier to get than dealer stuff. Blue bottle is what you want. Can be found at Walmart

 

Could you explain what you mean by if I don’t know history? Like it could be harmful? I feel like I haven’t had a drain refill done in 100k…

 

No

 

He means if you bought the truck at 150k miles a don't know if the fluid was ever changed then it's best to avoid a full flush. The safest way to service the transmission is to do a series of drain+fills. As others stated, the transmission holds around 13 quarts but you'll only get out around 4 when you open the drain plug.

I use Valvoline Maxlife ATF.

 

What he's speaking to is potentially urban legend or superstition. I grew up hearing the same thing for electronic transmissions, specifically: "Never change the trans fluid if it's over 100k miles and hasn't been serviced, or you don't know the vehicle usage history". The claim is, by completely replacing heavily worn-out, low-lubricity, no-detergent fluid with more modern, full-strength detergent, high lubricity fluid puts you at risk of over-cleaning, dislodging something that's built up over the years, and killing your tranny. OR removing the buildup on the moving parts would maybe cause slipping.

Sounds plausible, but is it true, though?

You'll find claims of it happening on the internet, usually from the owner, but even from people working at shops who've "seen it with their own eyes". But what you don't hear: What was going on with the tranny in the first place that made someone think a fluid change was required? Did they change it because shifting was already not happening correctly or happening erratically, gears were missing, shifting was difficult, or what? Normal people don't just up and decide "Oh hey, I'ma flush my tranny fluid today", and most shops don't push trans flushing as a service.

The other thing is - what make/model and trans was it that died, and how many miles, so we can compare apples-to-apples to our 1GT transmissions? Like, with GM's 4l60e, I beat up on 'em online often, they're pretty much flawed electronic shit versions of the 700R4, prone to dying after 100k-140k miles anyway. If someone had 160k on a 4l60e and did the first fluid flush on it, I'd expect it to shock that poor thing to death, but so would pulling anything with it Bottom line: It's nowhere near the caliber of what Toyota puts in our trucks.

IMO, it's speculation. And since - miraculously - after 20-30 years of electronic transmissions being a thing and these rumours floating around, I haven't seen a single person show definitive proof of it, I'm calling bullshit. I find that weird, don't you? Sort of like UFOs. How is it everyone has a camera on them (smartphone) these days, yet UFO sightings have gone down? I believe UFOs exist, no way we can be the only life forms in this universe. But it's weird that, given all the cases prior to this modern technology, case numbers haven't exploded, y'know?

Is it safe?

Rather than answer, I'd say this:

• If you're worried about it, do drain/fill sessions at intervals, over time. Over the next year, every 1k-2k miles, drain the pain and refill exactly what you drained out w/the recommended Toyota fluid.
• For the new sealed transmissions (2005-2006), Toyota has recently reversed course and stated (iirc) 60k miles is the recommended flush interval, or was it 80k? I forget. If you're over that mileage, you may want to consider a flush to get back on maintenance schedule again. No reason you can't drain/fill though.

 

I suggest you do some research on the topic.

A "flush" at a typical transmission service place is dangerous. Period. They use an external pump to force through the transmission the old fluid to add new. The force tends to break things loose that are best left alone, especially on older transmissions. It's a good way to have transmissions problems or downright failure.

Draining and refilling is something, but it takes a long time to replace all the fluid, for a number of reasons.

IMHO the right way to do it is to have the built in transmission pump in your truck take care of cycling out all the old fluid while new fluid is added. It's apparently not that hard to do, if you know what you're doing. SOME dealers will do this, and do this properly. Considering how nasty transmission fluid is, and what's at stake, I have no problems paying a dealer to do it, AFTER I vet them to see precisely what they do (don't put words in their mouth) and why.

Other dealers will drain and refill, which really doesn't do anything.

 

"Doesn't do anything" isn't really accurate. "Doesn't do anything quickly", is more like it.

Drain/fill is effectively diluting the old fluid with new fluid. Each drain, you're reducing the concentration of old fluid, adding in some new fluid, and with each subsequent drain, removing some of the mixture. All fluids have detergents. Any time you add fluids, you're adding detergent into the system. Neither of these are "not doing anything".

The concept is pretty simple to prove with glass of orange juice. Take a measuring cup with 6-8 oz of OJ in it. Remove 1.5 oz, replace with water. Repeat it a couple of times. Within 3-4 fills, the OJ will start to get lighter and lighter. It'll never get past 'hazy water' stage, translucent at best, but you can clearly see there's definitely more water than orange juice.

At the end of that process, half a dozen flushes in, doing a complete, proper, low-force flush 5-15k after that point is probably the best way to get back there.

Toyota is pretty picky about the process they use; they won't use the high force machines. Timmy shows one of the better ways to handle a full flushed on trannies if someone wanted to fully clear out. Neither of these transmissions died after the maintenance, or he'd have posted about it...

Non-sealed (w/dipstick, 2000-2004):

https://www.youtube.com/watch?v=RumPXivBlk8
​

Sealed (no dipstick, 2005-2006, Sequoia 2005-2007, IIRC):

https://www.youtube.com/watch?v=gx5dU3UVcRs​

 

You're correct. I used a poor choice of words.

I bought a '98 4runner once with 200k+ miles on it. When I drained the transmission fluid, it came out coffee black and thick. I did the drain/refill thing many times to get the ratio of new fluid up to make it "mostly new" fluid. Wasn't fun, nor pleasant. Transmission fluid is nasty! I ended up dropping AND changing the pan (bottom of dip stick was broken and stuck in it) and changing the filter as well (which solved the stuttering on acceleration issue). At the end of the day, I put a LOT of transmission fluid in there, most of which ended up just going to the recycle center. That probably jades my perspective.

Since then I pay a dealer to do it after I vet them. Considering most of the price is the cost of the fluid, I considered it a brainer.

 

Totally agree, dealer is great for fluid changes that should be covered against damages and to spec, with OEM reco'd fluids. Diffs, power steering, coolant, trans, brakes. Oil is too easy to do yourself. It's arguable diff isn't hard, but tell that to some people who came here complaining after not using the correct fluid

Good part about 1st gens is, at least w/my later model, trans filter isn't a cloth/paper filter, more of a screen. One less thing to deal with, one less thing to jam up.

 

I would do the 4 quart drain/refill. Make sure to do it cold, not warm and on a level surface.

Also make sure to get a funnel that will fit the dipstick tube since you'll be putting in new fluid that way on your 2001 Tundra.

Also, go with synthetic ATF that is Dexron III backward compatible if you can. Wally world has some, I cannot remember the make.

 

Yeah I forgot to double check the funnel. The first time I changed was a little rough on refilling. Got the right funnel after that.

 

Well said... and 100% agree.

To OP: here's how you do a flush: (pics included to show exactly which line to use at the tranny cooler)

https://www.tundras.com/threads/2006-transmission-drain-fill.68123/#post-1774161

Regarding funnel: there's one shown in that thread which is a great one to have and I highly recommend it. But regardless of what funnel you use, make sure it has a positive air-tight seal on the inside of the dipstick tube. If it doesn't, then as the fluid displaces air in the tranny the air coming up the dipstick tube will cause the fluid to back up and overflow.

 

My funnel isn't airtight, but I just pour it very slowly and stop 1/2-3/4 way up the funnel so the backflow from air doesn't push the fluid past the rim of the funnel accidentally.

 

The only thing I never understood about that method - and maybe it's because there's not enough uptake suction on the return line - but why not get two measured 6qt-8qt clear Lexan/Cambro buckets and:

• Leave one empty, dump 4qts fresh Toyota WS into the other
• Pull both tranny lines off the radiator
• Put supply line into the waste bucket
• Tie a weight to the return line and submerge into the WS bucket
• Start the engine and watch until you see new fluid dumping into the waste bucket, shifting P to 2 (or L) as necessary
• Button up everything, and follow FSM to confirm fluid level

Seems like this would absolutely give you a full flush, with no special tools, while cool, and with no forced pressure.

But obviously if there's not enough vacuum to suck up the new fluid, it absolutely explains how/why folks don't do it this way. You'd essentially run your transmission dry.

 

The transmission pump motivates the fluid via positive pressure -- there's no vacuum on the return line. I imagine you could gravity-feed fluid back into the transmission via the return line by connecting a funnel to it. I've never done it because the dipstick tube is a more convenient delivery path. But if I had a sealed transmission like the later model trucks, I would certainly give it a try.

 

The problem I've encountered isn't that it backs up into the head of the funnel, but that it backs up in the dipstick tube, which causes an overflow where the funnel tip meets the dipstick tube. (if that makes sense)

 

Strange. I haven't run into that issue. Maybe mine is somewhat airtight or at least tight enough so that doesn't happen.

 

Not sure that sanctimonious douche would post anything he did wrong, and fairly sure he'd mute/hide any users who disagree on any of his videos. He's a 50 year old entitled man child.

 

Got it. I don't watch his videos often, I've only seen 3-4 here, one swapping out a gas tank, two on tranny fluid change, and I don't remember the other, diff breather reloc? There are definitely people whose channels I prefer to watch, Toyota-Mechanic (German dude) is one of them. Guy is super wholesome, grandpa vibes.

 

Huge fan of drains/fills here. It only takes 2-3 to see much cleaner fluid. I like to start them around 50k and do one annaully. After a few years, the fluid will be bright and clean. Believe an annual refresh of the additive pack is better than one full change every 100k.

When I buy a car over 60k or so, I'll do 2-3 changes to get the fluid brightly colored again.

 

This is the funnel I used but I realized I lost the hose during our move so I've got to buy a new one. It works perfectly.

https://www.autozone.com/shop-and-g...kins-blue-18in-transmission-funnel/557785_0_0

 

I used one of these I bought at either Autozone or Advanced Auto years back.

$2 FloTool 10701 Spill Saver Multi-Purpose Funnel, Assorted Color

https://www.amazon.com/FloTool-1070...words=Engine+Oil+Funnel&qid=1668188804&sr=8-7

 

Ditto. Two actually, I cut one of them about 3" shorter on the pointy so it fits more nicely into the oil fill tube. Black one for oil, orange for other stuff.

 

I just realized this is in the 1st gen area, back in the day when you had a way to add more fluid one way or another. In my gen, it's all "sealed". Apologize for any confusion.

 

Don't apologize, that transition happened with 1st gen, everyone over here with '05 and '06 are in the same boat as you, believe it or not...

 

I did a flush on my 96 Camry by just pumping out 4 or 5 quarts of old fluid from a return line while running in park or neutral then filling back up (after a couple drain and fills). It stopped shifting gears (was stuck in 2nd I think) so this was a last ditch effort. Fluid was in terrible shape. Still shifting ok now. Don't see why you couldn't just pump some fluid out of a cooler line and refill just don't run it too low. But if you have a drain plug that isn't stripped (mine was) then it seems drain and fill would be better/easier.

 

I’m over 310k and I’m positive my trans hasn’t been touched.

 

Have you had a bad interaction with Tim? I don't know him personally, but he's an active member of the 3rd Gen 4Runner community, T4R.com. In my interactions with him he's always been easy going and generous with his knowledge. He hosts tech days at his home and and is very well liked and respected. In my opinion he's an exceptionally thorough tech and does a great job with his videos. I do all my own wrenching, but I'd trust him to do anything on my truck... not that he's offering. Your comment is literally the only negative thing I've ever seen/heard about him in years of interaction.