west709

so im about to do my tranny flush and wondering if its best to change the filter also, or will i be ok with just a flush and fill???

NTRUDA

your can change the filter or clean it if it's not too dirty. I would also not do a flush after you do this one but just a drain and refill from here on out if you are changing your atf when required...JMHO...Good Luck...

LScowboyLS

and use the real Toyota T-IV tranny fluid from the dealership, it's not that high priced ($5/qt.)

also, transmissions don't like the shock of all new fluid, they like drain & fill, so that only some of the fluid is replaced at a given time

and this is VERY important, Lexus specifies that not only the drain plug gasket, but ALSO the drain bolt, is a one-use item

I know that seems silly, but the bolt is cheap, like less than $3 at the dealership, and if you reuse the old one, then they tend to leak, not a good plan!
(I had to learn this the hard way!)

cobalt91

What year and how many miles?

PureDrifter

iTrader: (10)

power flush=bad
fluid exchange (such as shown on lexls.com) = good.

LScowboyLS

this is correct on a low mileage Lexus, or one that has always been properly maintained, but on a higher mileage car, say 125K+, don't replace all of the fluid at once unless you know it has been done before - some Lexus's have NEVER had the fluid exchanged or even drained, and the shock of all new fluid with its modern detergents can loosen deposits and clog internal passages and cause other mayhem resulting in a tranny problem you didn't have to have, even on the bulletproof Aisin. - if you don't know the full service history of a higher mileage car, just stick with drain and replace.

With drain and replace, although less than half of the fluid is being exchanged, it eventually becomes fully exchanged after a few cycles of this.

Lavrishevo

iTrader: (1)

What do you think I should do? Lexus of San Juan wants to do a flush and thinks it won't be a problem. After some research it appears that the service that was done in 2009 on my transmission had to do with a leak. I was mistaken and I thought that they had done the transmission flush at 50K miles but after the dealer looked into the work order it was only a repair. She now has 70,336 miles and the fluid does not look dirty but I don't want to hurt the system. Do you think I should insist on a drain and refill only because of the low miles or allow them to do a full flush?

PureDrifter

iTrader: (10)

please go search, it's been discussed to death.

high pressure flushes will do what you're talking about, but standard pressure exhanges which use the trans pressure generated at idle will not, since the system goes through far higher pressure when driven. Also, the type of fluid used in the trans now is very similar to what they filled the trans with 20 years ago.

OP- if the fluid isn't smelling burnt or dark then you probably doing need to do an exchange, however you can do an incremental change to keep it fresh by swapping out 2 quarters (the approximate amount that comes out when you drain the trans pan) every time you do an oil change.

Lavrishevo

iTrader: (1)

So I went ahead and called a few Lexus dealers in the states to see what they recommend. The told me that they usually don't start looking at the Trans fluid till over 100K miles. I did not realize that the LS400 had such a high mileage interval for fluid exchange.

So, if the fluid is clean and there is only 70K on the car it would be reasonable to assume that there is not much of anything built up as far as gunk goes right? Did not find out if the dealer does standard or high pressure flush.

LScowboyLS

I don't care if it has or hasn't been discussed to death, my closest friend, Paul Diegelman has probably rebuilt more automatic transmissions than anyone in America, and 100's of Aisin 340E's, A650E,s and the like.

if you change all of the fluid at once on a transmission that has it's original fluid after 15 years and a lot of miles, you have a much higher chance of creating an issue that you didn't have to have.

if You don't believe me or Paul, ask Aisin, or Toyota - they both recommend the same thing I am stating here - drain and fill ONLY, at least for the first few times until the tranny is internally clean again.

RA40

iTrader: (6)

Each car is an individual case to evaluate. While the fluid may spec to be 100K, if all the 100K was done in stop-go traffic, it will not be as happy as a highway driven car. I've not done a fluid analysis on mine because I do a partial drain each oil change interval. Ours has 2 quarts of fresh fluid every 8-10K miles. Maybe some member who runs the 15K intervals will be willing to do a fluid analysis and post results.

At 15K you'll see color changes and by 30K, it is becoming dark. 60K it isn't translucent red but burgundy. Beyond that, I don't want to think.

This is the big tranny fluid thread:
https://www.clublexus.com/forums/ls4...er-thread.html

Lavrishevo

iTrader: (1)

Good points guys. I trust your experience. I will start the drain and refill when I get back home. Honestly, I have always done the trans fluid at 30K on all the other cars I have owned. As I have only had my LS for 5 months now and as far as I know, she has never had any new trans fluid how many miles do you need to drive it before you can drain and refill again? I don't put on many miles as I spend a lot of time on the road.

LScowboyLS

I would go once a year on the fluid change and insist on Toyota T-IV (which is also available in a particular Mobil or Volvo bottle, but those are more money for the same fluid.)

I don't like to be repetitive but am repeating this because it is really important:

Lexus specifies that not only the drain plug gasket, but ALSO the drain bolt, is a one-use item!

I know that seems silly, but the bolt is cheap, like less than $3 at the dealership, and if you reuse the old one, then they tend to leak, not a good plan!
(I had to learn this the hard way!)