Bought my 4Runner used at about 110k and currently at about 160k. Its a 2008 v6 4x4 with the "sealed/lifetime" tranny.

Toyota service records from previous owner show no transmission fluid change. I haven't touched the transmission either. The transmission shifts with no issue.

I've been going a good bit of preventative maint on my car these past few months, and the thought of changing my transmission fluid came up. However, I'm hesitant after watching the two youtube videos below. I'd say both are reputable.

Scotty Kilmer on Changing Transmission Fluid: Don't change at all if car is old. Transmission on borrowed time. Thicker transmission fluid helps transmission function

Chris Fix on Changing Transmission Fluid: Suggests changing lifetime fluid, but not flushing. Flushing can gum up the valve body. Flushing has no downsides.

Should I change my transmission fluid? And if so flush or fill/drain?

Million dollar question is, what is the condition of the current fluid? If not terrible, I would do a pan and filter service. Forced flush is never a good idea IMO Get ready for the shit storm of a million different opinions on this topic though lol.

Lol. I changed the radiator on Friday and the transmission fluid was dark. No dipstick.

I don't do any serious towing, and neither did the previous owner.

I did two consecutive drain and fills on mine with 190K. Others will tell you to do a full flush until it runs pink through the cooler lines.

If you drain and fill, closely match the volume out to the volume you put back and you can forego the overflow process. Also, be careful as the drain plug is very easy to cross thread on the pan.

Didn't notice any change in performance, but gives a little peace of mind.

Just my experience...your mileage may vary

Pan and filter service is all I would personally do.

As in drop the pan, clean the crap, put in new filter, then reattach pan?

Yes. Measure the fluid lost when removing the pan and add the same quantity back in with fresh fluid.

Yeah, I'm leery of doing any flushing. Why didnt you go with the overflow as suggested in the FSM?

Do the complete fluid exchange by using the in & out cooler lines at the radiator. That's not a pressurized flush, just an exchange while the fluid is normally circulating.

Your transmission was designed to use a specific fluid, and the stuff in your high-mileage transmission is completely out of spec at this point.

You'll probably notice smoother shifting, better mileage, and your transmission will last longer with proper fluid and not that old, dirty stuff that's in there now.

Did you see Scotty Kilmer’s episode on “lifetime” transmission fluid? Change it by full exchange (not forced flush) as others have recommended. My local dealer did a full exchange for $179 or so. Thought that was fair since the fluid alone was $100+.

160 K on the odometer is not that much for these vehicles. I would definitely change the transmission fluid. Without changing it, at some point down the road you are guaranteeing you will be replacing the transmission and that will be an expensive job.

my '07 v6 has 202k miles w/original transmission fluid. spoke to two dealers about it. one does not have the setup for a full replacement, so recommend drain and fill. the other does have the ability, recommended full replacement (not a force flush, neither recommended that).

both said they do not recommend dropping the pan. the filter is a metal mesh screen. they only drop the pan if there is a leak.

so, find a shop that will do a full replacement, do not drop the pan (unless leaking).

cost depends on location. here, north of boston, retail runs about $250 before discounts. unlike oil changes, this only will get done about every 100k, so i don't mind having the dealer involved (the fluid alone is about $100). just use toyota ws. this is what the manufacture recommends.

I have an 05 V8 with 140k miles and an 07 V6 with 216kmiles. I've changed both of the files dropped the pans and done three full fluid exchanges. I change every 50k miles starting at 150k on the 07 and 100k on the 05.

So with that experience listed in will say this. You absolutely should change your fluid. Don't bother changing the filter. It's just a metal screen. The only reason to drop the pan is to check the magnets and clean out the sludge. Dont use a torque wrench. Using Valvoline max life is just fine. And drain and fills are just lazy.

Why do you say to not use a torque wrench??

I bought my truck with 136k on it. No records of tranny service, so I drain and filled a total of 1 gallon over the period of a weekend. Truck drives fine, and I have since gotten into the practice of doing a drain and fill every 10k since it's easy to do and I'm already under the truck greasing the drive line