5.7 w/240k...to drain & refill trans fluid or drop pan and change filter and 1/3 fluid ??

Walmart has Valvoline WS spec 4qt container for 21.99$ been using it a year, shifts fine.
It probably isn't as good as as the OEM fluid but that's ok by me.

 

OEM for me...taking good care of it. No public transit in Tejas!

 

You can buy a 5 quart jug of real live WS fluid made by Idemitsu on Amazon for about $11/qt. Idemitsu is a legit, large Japanese oil company that is an OEM supplier to all the Japanese brands and I used their WS in my 2008 Tundra with no issues.

 

Order from an online dealer like Fred Anderson which is I'm sure what @texasrho83 was referring to.

Fred Anderson has their sale going on right now for 1 more day so better act fast.

https://autoparts.fredandersontoyot...standard-automatic-transmission-fl-00289atfws

 

I have been utilizing the “full send” method on numerous high mileage Toyotas and it seems to work well. Not having to drain and fill numerous times to play catchup is nice too. No way would I drop the pan though.

 

What's "full send?"

 

Full fluid exchange, not just a drain and fill.

 

DIY or at a shop? Considered a fluid exchange all at once using the trans cooler lines, but simple D&F is easier for me given my circumstances. Home fluid exchange worked really well on my little 92 Ranger XLT a decade or two ago.

 

I use the tranny cooler lines and Aisin WS fluid.

 

Where are the lines on your '15? 5.7L engine?

 

The 15' has them in front of the radiator on the passenger side, my 2nd gen 2008 has the tow package with the big trans cooler in the same spot.

 

How many miles on the truck.

 

I will use my Sequoia as the example, purchased truck with around 185k on it. I did the full exchange sometime ago, probably around 250k, it now has 335k on it. I had no prior record of having a transmission service. My 2015 had 195k on it when I did the service but it only has another 15k on it, again no prior record of a service.

 

That method works well...wish my cooler lines were up front, mine are behind the radiator.

 

I did a full fluid swap using the transmission lines, but I accessed mine under the truck, passenger side - next to transmission itself. I pumped out all fluid until it was a nice clear red. I then immediately towed my 30 foot travel trailer to Colorado and back (2 mountain passes) with zero issues.

 

What year/model & engine/tranny combo? I have hard lines from the tranny almost all the way to the tranny cooler.

 

This is encouraging.