so, some may have read my posts about "inheriting" my wife's 2005 LS430. everything is great on the car right now & it's pushing 206k miles. we were going to sell it, but since i have been fixing things we were going to keep it as an extra car. but since it's more comfortable than my S40, i started using it as my daily.

since i've been putting my time in and fixing everything i started thinking about maintenance things like transmission fluid replacement. when i was a service manager at a Firestone, i had my lead tech do a transmission service on it while it was there. unfortunately for us, there was a clamp that came loose, and fluid ended up leaking. of course we didn't see anything, so she kept driving until it wouldn't go anywhere. so Firestone sent it to a indy trans shop. i knew the owners since working at firestone. he admitted he had never worked on a Lexus transmission back then. he suggested replacing the trans with a used one that he found that had less mileage (at the time, there was 110k on our LS430 & the used trans had 75k.) he said he give it the once over the best he could, and he "said" they flushed it with new fluid. they got it back to us and every that been good since.

now, my questions are since then, my wife has neglected the car (hence me fixing things like clock springs, and more). but with no service since the replacement, do you think it would be safe to have a trans service done @ 206k miles? or should i just leave it be since i do not have any issues & ride it until the wheels fall off. i'm scared b/c if a service is done and there are issues, replacing the trans may not be an option this time (b/c the car is not in the best of shape right now.....rust on the R/R wheel well, clear coat on the hood completely gone & looks like crap). i think that a trans replacement would be more than the car is worth.

is my thinking completely out in left field?

 

I did a drain and refill on mine ~128K a few months ago. Fluid was completely black. I am going to do drain and refill again soon (as soon as I can find free time over weekend) and then do it again (after a few hundred or thousand miles) until fluid is back to red. I am planning to drain and refill every oil change, or every other oil change. I do not believe in this lifetime fluid but that is just me.

I have not observe any problem, and maybe shifting is a little bit smoother. I am not the daily driver, only drive the car maybe once a week, so kinda hard for me to judge if it shift smoother or not, but definitely not worse.

 

There was a chart that showed 3 drain/fills resulted in 19% old fluid, and that was the desired outcome by most people.

On my wife's GM, since it has a dipstick, I did only 2 and it was pink. I was planning on 3, but went by appearance. This was at 71k, and Dexron VI is a little pricey. Plus it eats a drain plug as its tapered and I prefer not to fool with thread locker/sealer. The new one from the factory has it applied, and cost like $3 online.