So I 99% understand the transmission drain/fill procedure, but have two questions:

1. Some people do a drain/fill, then drive 60-100 miles before doing the next one. Others (like the video linked before), do a drain fill, turn the car on and shift gears, turn the car off, then do the second drain/fill, and so on... So, how much time/driving do you need to do between drain/fills?

2. What is the purpose of opening the thermostatic valve? The video linked before didn’t do that.

 

1. Follow the TIS procedure after the 1st drain and fill and then repeat as many times as you want (number of D/F) you want to do. There is no benefit to driving after the 1st, 2nd, 3rd. When you do the shifting thru the gears, etc, that is circulating the ATF.

2. I was told that when you "pin" the thermostat, you're allowing the ATF to circulate through the whole system during the gear shifting procedure and bypassing the thermostat.

 

I don't know if you guys have heard of this trick but if you drain while the front of the vehicle is elevated on ramps or jacks you get an extra 2 quarts or so out. This was discoved in the LS430 forum. Obviously, the refill process should be done with the vehicle level and at full operating temp but this is quite helpful for drain and refill process.

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Lavrishevo: Interesting... if it works in the A760F I wonder if it would present any refill issues? I can't remember AT pan capacity.

 

I get exactly 3 quarts from the pan

 

Am I the only one wandering if you drain it with the front wheels on ramps, how you get it back level to do the fill and level check properly? Do you just jack up the rear end until it's level with the front wheels on ramps?

Getting an extra 2 qts out of the pan was mentioned in an earlier post by someone who removed the pan but never fully explained. When I do my transmission service I'm debating sticking a bent tube in there connected to a syringe extractor to see if I can pull any more out of the bottom of the pan. (otherwise with the vehicle off, fluid will drain back down in to the pan to raise the level (but 2 qts?) Either way ya can't drain the pan with the vehicle on.. if the drain bolt is on the bottom of pan (which it appears to be) all the fluid in it should come out when off

 

One scenario I guess.... front on ramps with rears on ground, drain, lift rear by the diff, and then drop onto ramps on the rear tires to make it level

 

The drain plug is the LOWEST point in the pan, so there would be no benefit to try and grab an extra ounce of ATF.

If you want to possibly get an extra ounce, then also pull the check plug and you might a little fluid.

What amazing on the GX service manual, there is no mention of an ATF change procedure. The Lexus LX and also the Toyota LandCruiser have a procedure and the manual states to do 3 drain / fills.

 

Yeah... the FSMs do only talk about single drain and fills in AT fluid replacement chapters on the 460.

 

The extra fluid comes from torque converter not the pan. Well, technically the pan has more fluid in it when the front end is elevated as this fluid is not inside the converter. In other words, there's more fluid in the pan with the front end jacked up or on ramps. I think I have the correct part listed. I'm not a mechanic but I do play one on TV... Lol. I have rebuilt a few engines and do a good amount of maintainence myself but don't always remember the correct terms.

It's not a small amount. We are tallking quarts not a few ounces. The 430 has a very similar transmission, there is no reason why this would be any different. The 4.6 V8 is a bored out 4.3 with changes to the intake and heads from what I understand. Very similar engines. Though it's nice that it uses a timing chain vs a timing belt.

Obviously following the correct procedure to fill the transmission is very important. What I would recommend is to measure what you drain to get an idea of how much came out. Jack the back end up so vehicle is level for the refill or push it off the ramps maybe.

Also, Aisin, who actually makes the transmission for Lexus recommends servicing every 30k from what I have read. Lexus of North America invented this whole "sealed" transmission / lifetime fluid terminology. It's marketing BS to make ownership seem less expensive. There is nothing sealed about it. Just lacks a diptick. The guys getting 200k+ miles out of their transmissions service regularly.

 

For anyone looking at doing the drain/refill, these looked to be the cheapest measuring beakers I could find @ $10.49 each. They are extremely sturdy with raised & colored markings.

 

Those are NICE !!

I use these from Home Depot for the first drain to get an the accurate amount of fluid coming out. They're $2.70 each at my local HD

 

So I plan to do 3 x Drain & Fills this afternoon once my meetings wrap up for the day. I have all my parts/fluids/etc....

My rig is a new-to-me 2010 GX460 Premium (Build date Feb 2010) with 106k miles. No record of any A/T service on Lexus Owners History, Carfax, etc...

A few notes for others:
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1. OBD2 Reader: If you are a "car guy" and either have multiple vehicles or know you'll get other vehicles in the future, go ahead and invest in a good ODB2 Reader that can read the AT Temp sensors. I tried the VeePeak, BAFX, BlueDriver, and OBDLinkMX+. While you can get the other ones to work with tinkering, get the OBDLinkMX+. It is the easiest to setup and comes with Enhanced Vehicle Diagnostics for all Lexus/Toyota/Ford/etc... without having to pay for add-ons later.
   Amazon
   Amazon
2. Buy two sets of Rhino/Harbor Freight ramps...enough said.
3. I'll be doing a Blackstone Fluid analysis on the 10-year 2-month old tranny fluid. (Feb. 2020 build date). I'll come back here and post the results.
4. I plan to follow the instructions in the video linked here, but open up the thermostatic valve.
   You Tube

Wish me luck. More to come!

 

One thing I did was replace the hex plug (prone to stripping) with the same head as the drain plug.

GOOD LUCK !!!!

Can't wait to see the results from BlackStone. Since WS is the mystery fluid, it's going to be hard to know the original viscosity, but the wear numbers will be nice too see !!!

Your tranny will thank you !!!

 

Just for reference this is from my old 2004 LS430. I purchased I think around 85k and did the sample at my 3rd drain and refill. In other words, after 2 were already completed so this is based on 2 not 3. They were done about 12k miles apart or so.

I also remember reading Aisin does not recommend dropping the pan unless a repair is needed. There is no true filter. More like a screen and this does not need to be serviced.