RamAirRckt

My GS with 241k shifts perfectly (A650E, same identical unit as LS400/LS430) and only thing I have done is changed the fluid.

The first time I changed it about 4x in a row to make sure I got 90% of the fluid out, was putting in synthetic. Since I have dropped pan 2x, once to put in screen (unneeded, Lexus does not recommend replacing, it was spotless anyway), and the second to fix the leak I had accidentally started when I pulled for the screen.

While I was in there I bumped up the line pressure to the max position, but that was it. Still shifts perfect.

Fluid is soooo easy to drain and fill, just do it annually, adding 2-3 quarts as needed to fill it. Don't pull pan, don't do anything else. Just drain and fill maybe annually or once every 2 years. Flushing is unneeded as Lavrishevo said, it isn't like engine oil. It is a hydraulic system.

Most trans shops like the fluid changed every 30k-50k miles. Good rule of thumb, you can't go wrong with that.

jimbosr1

i had the trans fluid changed at the toyota dealer at 80k miles. they transfered all the fluid out while the new fluid went in and i have 101k miles now and have had no issues.it wasnt a flush so it cant say thats a problem or not.see if they have that machine that transfers the fluid.you can go to a toyota dealer and get it done.

Bocatrip

+! The clutches in the transmission will develop a build up of varnish which in fact is keeping the clutches from slipping. You don't want to upset this buildup unless you are already having issues with the trans. I'm a firm believer of either leaving the transmission alone from day one or just drain and fill. Flushing is too aggressive..

2GSKaizen

iTrader: (1)

Don't do a flush! I don't care what kind of crap they try and sell you on. This is what it comes down to. The drain and fill method is tried and true. It is a 100% verified solid option for giving that transmission the best chance for longevity assuming you start doing them now. The flush is risky business. 50% of people say its ok (I rebuilt transmissions for a while and am telling you it's not). The other 50% of people have had problems from doing a flush. Would you rather be safe and do the drain and fill? Or would you rather take a 50/50 chance at screwing something up?

swfla

iTrader: (1)

I'm confused. From everything I've read and what people are saying here, you're describing a flush if ALL the fluid was transferred out while all new fluid went in. A drain only gets about 2 qts. out which then gets replaced. It takes multiple services to get a "full" change. Are you talking about a third option that I've not seen mentioned anywhere? Is this a Lexus LS?

deagle

I specifically asked for a partial drain and fill and pointed out the temperature requirements. Lexus of Chantilly had no problem with my request and the service advisor even said he doesn't let people flush the transmission completely. Took about two hours and the car has been smooth for 5000 miles since.

jimbosr1

my understanding is a flush uses a detergent of some sort and a fluid exchange doesnt.i have a 2006 ls

Slvr surfr

iTrader: (1)

Hey fellas! This may not relate to the newer, better built A/T in our LS's but i'll share anyway. Years ago in 1996 i purchased a 92 Camry V6 with a lil over 100k on the clock. I drove the car for at another 40-50k miles and as far a i knew, the trans fluid had never been changed so i took it upon myself to change it out. Did the work myself as i was a young, mechanically inclined novice at time(21y/o). Didn't do a total flush per se but did a drain and fill or whatever came out i put back in. After the first job, i ended up doing it again about a week later for some reason i forget. But after the second drain/fill, the trans went one night while i was driving. Ended up getting it rebuilt poorly by some trans shop and it was never the same and neither was i. This is whats making me hesitant about messing around with my trans on this car which is in another galaxy as far complexity. I do hear good stories on how ours trans will handle the D/F with no problems as long as there is no preexisting issues which don't seem to be the case in my ride now. She shifts perfectly. Anyway, i just wanted to share my one and only trans story and hope this is an isolated event and will be getting my D/F done real soon as she does have 175k on the clock.

Lavrishevo

iTrader: (1)

There is a power flush and just a fluid exchange. Not sure if a detergent is used in a power flush. Really, as mentioned before, it is best to introduce new fluid gradually. This particularly important to how the clutches wear. This is why drain and refill is the best practice. Slow introduction of new fluid.

jimbosr1

in my 06 ls owners manual supplement book at 144 months or 120k miles it says to change the transmission fluid with a side note that says replace only if vehicle is operated primarily while towing.go figure.

swfla

iTrader: (1)

Thanks for responding and Thank you for your service to our country.

jimbosr1

thank you sir!

Lavrishevo

iTrader: (1)

Honestly, I trust Aisin over what Lexus says. The morons called it a "lifetime" fluid in the U.S. Only. Aisin actually make the transmission. Outside the U.S. I believe the schedule is every 40k or 50k kilometers. Seriously, look at the practice of LS400 and fellow high mileage 430 owners for real world results.

AJT123

Thanks, everyone. Gotta love CL forums. I have decided to do the drain and refill.

I agree with you all that it's the safest way to go, especially since it has been tried and true.

I will note, however, that I still haven't seen anyone on our forums that's had a problem after a flush (at least when done at a Lexus dealer), so that was one reason that had me considering it.

Definitely. Tried and true. But I have one more question: Does said drain and fill process with the old cars without the sealed unit work the same? Is it a slow, gradual process like on our cars? Or is a drain and fill (on the old cars) a complete fluid exchange?

Lavrishevo

iTrader: (1)

Yes, it's the same principle with our cars. Not much difference between the years really. 04-06 got an extra gear and synthetic fluid instead of type IV. Even the 8 speed in the ls460 is quite similar. I would estimate that synthetic fluid takes longer to break down so this may be a bit of a benefit.