So for starters, this isn't a "this is what you should do" guide, it's a "this is what I do" guide. The 2016 Toyota 4Runner Warranty and Maintenance Guide says to "Replace automatic transmission fluid" every 60,000 miles under "Special Operating Conditions". I have never seen any other official interval of changing the ATF from Toyota for a 5th gen 4Runner. With that said, most vehicle manufacturers are constantly trying to improve their "cost of ownership" number so they can brag that their vehicles are "cheaper to own". One of the biggest methods they use is to increase the intervals of replacing fluids. Toyota even says that you can wait to change your motor oil every 10,000 miles..... LOL. Don't do this. I replace mine every 7,500 and it STILL comes out the color of tar.
Anyway, back to the transmission. Vehicle manufacturers will put a warranty on transmissions, basically based on how long the transmission will reliably operate before the fluid needs to be replaced. The problem with using this number yourself can be answered with two points:

1) The damage to a transmission from old fluid usually happens long before there are symptoms of the transmission failing. Think about smoking cigarettes for 10 years. You might not notice any health problems for the first 10 years of smoking! But does that mean that you can smoke for 10 years and you'll be just as healthy as someone who never smoked? Of course not.

2) After the warranty for a transmission expires, any damage that was not diagnosed and caught during the valid period of the warranty is now YOUR problem. But don't worry, Toyota will gladly charge you $7,500 for a new transmission plus $4,000 in labor! HAHAHAHAHAHAHAHA

Chances are, if you wait 100,000+ miles to touch your ATF, your transmission is already (to some degree) damaged.
I hope this answered all of your questions.

So why happens if you forgot to do this?:

“CAUTION: After removing old filter, but before installing new filter, re-torque the 19 transmission valve body assembly bolts!”

Very, very high chance that nothing will happen. I tried torquing mine, but not a single one was loose. This step is more for peace of mind. If these bolts get loose, then the transmission just won't perform quite as well.
If you didn't tighten these, I wouldn't worry about it, personally.
The biggest reason I included this step is for completeness.

Thank you so much for responding. Your post has been so valuable to us DIYers! Much appreciated.

Great Post
Great references

Something came up on my oil filter order that everyone should be aware of.
I ordered the correct oil filter from Amazon and upon checking the actual filter inside the box it was not correct, but the filter that is roughly 1/2" shorter.
So that is going to be returned to Trader Joes.

I ended up ordering the correct YZZA5 for pickup from a Toyota dealer for half of that price, pleasant surprise.

So always double check in the box.

There have been numerous reports of counterfeit oil filters, spark plugs, air filters, etc. Maybe you got one.
These items are best acquired directly from a Toyota dealer. Either local or online dealers.

Wow, thanks. I can imagine the work you did. A not in one night job.
You use the word "flush" in, seemingly, - or possibly different ways. The full service station flush, with a dedicated machine, is recommended against by (as he was referenced) Scotty Kilmer. He shows how one can get a 2 -3 quart drain and refill done, with a small handheld pump.
It is possible that flush was used by you as your own flush, rather than the machine flush at a service station.
In any event, what a helpful compendium of data. Thanks, again. Jerry

Ohhh ya, when I get time I will go back and edit it this to either say "D.I.Y. Flush" or "Fluid Exchange". I also agree with you in being against getting a machine flush from a garage or dealership.
Thanks for the catch!

And, again, thanks for all your good work. Jerry

Bravo! Great post sir!

I change the oil every 10,000 miles using synthetic and it comes out clear, only slightly darker than the new oil. 2014 SR5 with 265K miles.

I just flushed the transmission using Valvoline Max Life Synthetic, which is what I used the last time. The old fluid had been in 140K miles and I could not see much difference in clarity versus the new. In contrast, when I did the first flush of the Toyota ATF, that stuff was obviously darker than the new fluid going in.

[QUOTE=DougEFresh2;3474584]

Drive Shaft:
Fluid Change Interval: 15,000 miles / every year – whichever comes first
* for hard use (towing/loading): 7,500 miles / 6 months – whichever comes first;
*deep mud/water: As soon as you get back from off-roading.
Toyota Fluid: N/A
Preferred Fluid: (listed below)
Spider Grease: Classification: Lithium base chassis grease, NLGI No. 2
(Preferred: Lucas Oil Red 'N' Tacky #2 (10005))
(Good Alternative: Mobil 1 Synthetic Grease (105527))


Mad props, DougE. Your list is an excellent source for everyone, even those with years of experience turning wrenches. Finding all this information in one place is almost as good as having the FSM! Oh wait, you hooked us up with that, too!
Now I'm off to see if I'm missing with the "15k Driveshaft fluid change interval". I'm assuming this means add a little grease as with most other vehicles I've ever touched, but I'm not convinced I know what the latest tech may be.

Thanks again for all this work!

Thanks a lot for this document @DougEFresh2 !

I have a question on the front differential fluid check. The DIY video you linked is very helpful but I was wondering if it's recommended to change the plug gaskets like that person does? Or you listed the part number just in case? Thanks!!

That's a good question, I suppose I could have made that more clear. So basically, just because I have listed a part in this guide, does NOT mean that you have to replace it.
This might not be the best practice, but I have listed every part for all of the main components that are detached at any point during maintenance.
I have also listed parts in which the torque can be verified without too much trouble and any part that has a limited lifespan that's associated with one or more of the main maintenance components.
I feel this was a good decision because anything that is removed from the vehicle for maintenance has the chance of being damaged or getting lost.

As far as gaskets go, rubber gaskets, like O-rings can be reused one time as long as they're properly lubricated and changed at the recommended intervals, but the metal, crush washers should really be replaced any time that bolt and washer are removed.

@DougEFresh2 : I really appreciate your thread . Thanks.