Anyone here did drain and refill with filter change at high mileage? (Over 100k miles).
im not talking about full flush but drain and refill around 8 quart.

I have 132k on mine and never did any transmission fluid change.
Thinking about draining and dropping the pan and changing the filter and put back in what comes out.
This process it will drain out 7-8quart and total transmission holds around 21quarts so it’s like changing around 1/3rd oil which will refresh the old oil.
im a little paranoid but wondering anyone did it at this many miles (130k)?

 

https://at-manuals.com/manuals/lexus...y-instruction/

total system may be 8+ quarts , but drain and fill probably is 4 quart

 

so if I drop the pan I’ll get out 4quart?

 

give or take, yes

 

This has been discussed a lot. See these older threads which also contain detailed instructions. There is a complicated procedure designed by Toyota (to annoy DIY folks) to get the fluid level adjusted correctly. It is explained in some of these links.
FYI the total fluid in the transmission is only about 7.3 quarts. Not 21 as you stated. Read the links below and learn about your transmission, which is the Aisen U660e model.

https://www.clublexus.com/forums/es-...ans-fluid.html
​​​​​​https://www.clublexus.com/forums/es-...with-pics.html
​​​​​​https://www.clublexus.com/forums/es-...000-miles.html
​​​​​​https://www.clublexus.com/forums/es-...uid-flush.html
​​​​​​https://www.clublexus.com/forums/es-...placement.html

 

I flushed mine at 146.5K. Now has 177K. boy did I flush it. drained it, filled it. drove. leak appeared. drained it, put new gasket on, filled it, drove. still leak. repeated one more time. STILL LEAK. finally, went to dealership to get gasket. huh, thats odd, the aftermarkets were all rubber, dealer is steel. You know, like the one that was on there but it took me 4 times to figure it out. Sometimes I amaze myself! drained it, put STEEL gasket on, filled it again, mind you, each time with new fluid. WHY, cause I'm just built that way. ANYWAY. runs like a kitten and NO LEAKS!. no slips, smooth as butter, its ALL GOOD. Be sure to use correct fluid and follow procedure correctly. don't want too little or too much fluid in there. that WILL GIVE you problems!

 

Also some who have done this state the OEM transmission filters are much better than aftermarket filters.

 

I changed the filter each time as well, why not, I had it. The filters all looked high quality. I did not do any laboratory testing to see which one filtered better.