Any time somebody replaces fluid in a sealed transmission (sealed because manufacturer believed regular servicing is not really required for a typical lifetime of the component/vehicle? ), there is an element that something wrong *could* happen: wrong fluid used, incorrect amount, not closed properly again, foreign matter accidentally introduced, etc.
Any of which could render your transmission/sealed component worse off than not having changed the fluid.
Also, is there any way to measure how much better the car performs after such a fluid exchange in a sealed transmission?

Did I mention the various times (all many years ago) when automobile mechanics:
Left a pair of pliers inside my engine compartment which I discovered 2 days later?
Left the diagnostic port open with pins sticking out of it?
Lost a metric wingnut securing the circular air filter cover, and replaced it with a hex nut? Wingnut had fallen dangerously close to the radiator fan, which I discovered a week later.
Incorrectly wired my radiator fan, causing it to be ON at all times, instead of just turning on when the radiator gets hot.
Replaced a radiator hose with a non OEM hose (hey, a hose is a hose, right? ), causing a cooling air channel in the engine to become blocked?
Imbeciles. Sorry.

How confident are you of your mechanic in dealing with working with your car?
Golden rule of Engineering: if it works, don't mess with it.
(especially if it is sealed)

Just my $0.02...

Sent from an Android device using IB Automotive Group forum reader.

 

Agree with this post. And don't forget the ancillary rule of DIY'rs everywhere: If it ain't broke, fix it till it is.

 

The reality is transmissions that never have their fluid exchanged will wear faster then those that do. It was designed to either drain and refill or be flushed, The first being the better way to go about it. The statement that if it ain't broke don't fix it is hard to apply to the breakdown of lubricants.

If anything, the ls400 forum is testament to transmission longevity. Drain and refill. I let my Lexus dealer do mine.

 

Is DEXRON IV what we should use now or a bottle of Power Steering fluid good enough? I'm going to do the turkey baster remove and replace a few times over the next month.

 

 

I'm assuming DEXRON IV then? Recommended looks to be DEXRON II or III with II not really being available anymore and IV looking like it's taking the place of III.

 

 

I used synthetic Redline Power steering fluid... Steering feels smooth as silk.

 

Picked up some trans fluid from Walmart that said it was compatible for any DEXRON III. They didn't have any DEXRON III specific oil, it all looks to be DEXRON IV now.

So, started my pump out/in of fluid from the reservoir and the fluid that came out was really dark and had a dark green tint to it. I'm assuming that was due to the type of fluid that was previously used. I put it in the same clear container from where I had put the power steering fluid from my wife's Pilot and that fluid was just a dark/black color. Even on the paper towel I used for clean up you could see the green tinted fluid.

I'll be removing/replacing the power steering fluid every couple of weeks over the next couple months and then I'll make it a regular routine when changing oil. My LS is just under 130k miles and my guess is that the power steering has never been changed.