bclexus

UDel

Was this on a 4th Gen Lexus GS350? Is this a Lexus mechanic? Take it to a Lexus mechanic. If they say the transmission needs to be replaced, it is damaged, ask why, what would cause that. If they say anything about the fluid being bad(don't mention fluid until they look at it), needing changing say it is"lifetime fluid" and is not supposed to need replacing. Say Lexus needs to pay to replace the transmission because their "lifetime" fluid failed. I still want to hear what they say to someone who needs their transmission replaced due to the fluid if they will cover it since it is "lifetime" fluid and is not supposed to be changed.

JeffKeryk

I plan on taking a slightly different approach.
I will lift and level the car, drain; measure and refill the transmission.
Then run the car for maybe 20 seconds, to cycle the fluid out of the pan.

I will repeat this 2 or 3 more times, examining the drained fluid color.
Following the final iteration, I will run the car until the transmission temp reaches 113* (have to look it up).
This is easy with a OBD 2 module and Andriod app.
Then do the overflow process to (hopefully) set the correct level.

I will probably replace the filter; this good forum has advised using the Toyota filter.
I understand aftermarket filters are junk; it would be better to leave the original alone.

It seems to me if you run the car for any length of time, you are mixing the old and new fluid; my goal is to minimize this mixing.
Finally, I am using Idemitsu WS equivalent fluid, as it is synthetic. My understanding is WS is not synthetic.
This is my plan; you are free to take what you wish from it.

A simple periodic spill and fill would also be a good plan, in my opinion...
All my other cars get that.

I don't believe in lifetime fluids; your results may vary...
Good luck.

Cwang

I bought a genuine filter and gasket but I'll probably wait till it's 150K service to do that. I believe adding new fluid replenishes protective additives, I don't think the fluid breaks down unless it is abused.

I don't believe in lifetime fluids either. Neither does Lexus HQ nor Lexus Australia, it's just Lexus USA that wants advertise their vehicle as cheaper to own. I'll be sticking with WS though, I'll use their specified fluid and change it when instructed!

azipod

A good time to change the fluid is 60k.

There’s no such thing as lifetime fluid. All that means is that it’s lifetime until your transmission fails. All fluids will degrade over time.

The term lifetime fluid was coined by the auto industry to promote low maintenance.

Try using that term in the aviation industry. Aircraft mechanics will laugh and the passengers will run off the plane like there no tomorrow. I’m sure you would too.

bclexus

You won't be doing much in terms of blending the old ATF and the new ATF if you just "run the car for maybe 20 seconds". I'm not even sure what you mean by "running the car" - does that mean running the engine or actually driving the car and shifting gears? Regardless, 20 seconds of running the car (whatever that means) won't be blending much. You want to blend the old ATF and new ATF by driving the car (say ~50 miles or more) stop-and-go city driving and highway mileage with the transmission shifting in all gears and going through its paces. This allows the detergent additives of the new ATF to gradually remove varnish, etc. from the transmission's tiny ports, crevices, clutches and bands.

You can use the Excel 'ATF Drain-and-Fill Calculator' (using Excel Cells C5 & C6) to determine what percentage of old ATF remains versus the new ATF after each successive drain-and-fill.

JeffKeryk

Actually, I mean the opposite. The car will stay lifted; I will start the engine to start cycling the fluid out of the pan into the transmission.
After perhaps 20 seconds, I will shut down the engine and perform another spill and fill.
The 20 seconds should be sufficient to drain and cycle the fresh fluid in the pan.
The goal is to avoid mixing the old and new fluid as much as possible.
I will examine the fluid color with the goal of seeing fresher fluid after a few iterations.
The problem with running the car for a period of time is explained by the calculator; you keep diluting fresh fluid with old.
As you know, the amount of fluid drained each time is less than 3 quarts; that ain't much.
Finally, I will perform the Lexus recommended fluid level setting.
I will post my results at a later time.

bclexus

I really don't understand how you are going to avoid mixing (blending) the old ATF with the new ATF that you will be adding to replenish what you drain.

JeffKeryk

There is no absolute way, of course. But perhaps mixing (diluting) can be minimized.
You have seen videos removing the return transmission fluid cooler line, using the transmission to pump fluid into a container while idling the engine.
Generally pump out 2 quarts, stop engine, refill, repeat. After a few iterations the fluid runs clean.

I am attempting to do something similar.
As your Excel spreadsheet shows, it takes numerous iterations to replace a high percentage of the fluid, especially with less than 3 quarts per drain.
I do not want to drain, fill, lower the car, drive, etc for a bunch of times. That highly dilutes the fresh fluid and would take forever.
Plus, I want to do the Lexus level check 1 time.
I guesstimate that 3 spill and fills, with approx. 20 seconds engine running to drain the pan in between, should be sufficient to replace 60% or more of the old fluid.
Should be somewhere around 7 to 8 quarts new fluid. I will examine the drained fluid for color each time. It should improve.
Why 20 seconds? That should about the time to move 2 to 3 quarts of fluid. Dunno for sure.
How well will it work? We will see.

If the fluid comes out cherry red after the 1st drain, I might stop at 2. But I doubt it will. The 1st drain will be telling.
Almost every transmission service I have ever done has really dark fluid. CVTs as well.
The 3 Acura TSXs (1 2006 and 2 2007s) have been notable exceptions.

bclexus

I've never seen a transmission filter that looked like it really filtered anything from the fluid.

To my knowledge Lexus only offers a transmission flush, which if you study-up and research a 'transmission flush' you learn that it can cause more trouble than doing nothing because a flush tends to stir up the varnish and grit from the heat and lost friction particles from the clutch bands that can clog the tiny ports (holes) throughout the transmission's internals. I've never heard of Lexus doing a transmission drain-and-fill, but I guess maybe they would. I feel sure places like AAMCO will do it.

Handi

Replace the fluid and then run a magnet through it and you will know.
The manufacture doesn't want it replaced, guess why? Maybe so they can sell you a new one.
If your going to keep your car past 100,000 miles then change it. If your going to get rid of it then don't.
If your going to sell it then your records have value, if you will trade it in the dealer doesn't care about your records.
Good Luck either way

ItzFilyO

Can u really feel the difference after changing a transmission oil say after 150K miles? Or is it just a placebo effect?

bob256k

Transmission fluid change is listed for the JDM gs350 in the lexus maintenance schedule, just not for the USDM car.

Davenlei

iTrader: (1)

So if you don't have the scan tool, what is the process to get the GS350 into the "temp check" mode? Is it the same as for the GX470 for the ODB jumper points with a wire to short and the shifting from N to D several times as identified in the screen shot? The temps in the screen shot are for the GX470 and I am assuming from what was listed in the thread for the 2013 and up GS350, the temp range for the fluid level check is 102-120 degrees but I am assuming if the ODB jumper method is the same , then you only have to pay attention to the ATF Oil Temp light staying on when checking the fluid level...

Let me know if I am correct or way off base on how to do it on the GS350.

thallium

You enter the jumper pin method the same way, however I believe the temps for the check range are different in the GS350. I don't have the official temps but I compared the temps I was getting from my OBD app to the D on and D flash when using the jumper pin method and got D on: 119.8, D flash: 127.6. I also compared my Fluke IR thermometer on the bottom of the pan and the Fluke was reading 2 degrees hotter than the OBD, ie 121.8 and 129.6. I just used my OBD app while I was under the car so I didn't have to sit in the car watching for when the D came on.