I'd consider those pretty accurate. If you are going to use an OBD product to watch AT temps I'd first confirm that is working correctly before advancing with this maintenance

 

Thanks! Do you know what size wrench’s are needed for the three bolts? Can not find them anywhere

edit:
14mm for drain bolt
5mm hex for check bolt / overfill
24mm (15/16 fits better for me) for fill bolt

 

Good question and I thought I had documented that in my offline notes but can't find them.

IIRC.... Fill bolt is 24 mm.... drain is 14 mm and can't remember what hex size the check valve is. IIRC it was 4-6 mm sized hex bit

EDIT: looking around I think it is 5mm on the check plug

 

Definitely had crush washers on both drain and check valves. I bought extras. The fill uses a rubber gasket.

 

You were totally right, crush washers fell into the oil lol. Bolt is also 14mm like you said, my eyes are playing tricks on me. I drained both the drain and overfil bolts, only got 1.74qt out...

Do you think the excess is stuck inside the cooler and lines I ran?

 

The least I ever drained was 2.68 quarts on first drain. Always a chance it might be factory under-filled but think I remember someone seeing that amount on drain as well.

Second drain was 3 quarts 13 oz... third and 4th I just drained and replaced with four.

If you end up putting back in about 2.5 quarts and check valve doesn't show anything when you open at 115 degrees you will know that it is low. If you filled up the cooler before terminating it sounds like you should have enough.

How many miles on your '18? Fluid color look alright?

It wouldn't hurt to put in 3 and drain off the excess just to make sure you don't have to let vehicle cool and add more fluid. Make sure you pin open the AT thermostatic switch too so that fluid gets circulated.

 

Color at 90k miles, first drain.

Color at 90k miles, first drain.

Just wanted to add my two cents to this database. 2013 GX Premium with Tow package and 90k miles. Must be first drain and fill considering the color of the fluid...

Was a little apprehensive when it came to getting the truck into the temp check mode, but doing so with a paper clip was simple. Thermostat was secured with a bigger paper clip so now I have 2 new special tools?!

Plan on waiting 100 miles or so between drain and fills. Toyota WS was the fluid. The factory fill was at the proper level. Did not use new washers yet, will do so at the last drain and fill.

Thanks all for the discussion and uploading of the FSM. Love saving $100's!!!

 

Looks similar to mine (Post 64) at 55K miles.

https://www.clublexus.com/forums/gx-...l#post10478741

Are you planning on doing a few more in the near future?

 

My plan is to change every 100 miles or so. Bought a couple cases of WS for 12 quarts total and hope to get 3 more drain and fills.

I did read one of your latest replies stating you drained more with the second through fourth drain and fills.

Thanks again for your information posting!

 

My experience has been one always needs to measure drained fluid volume if they aren't doing the factory recommended level check. It won't be the same each time. 4 quart drain and fills are what I will go with annually.

IMO: Actually.... I find the Lexus/Toyota factory check method better than AT's with a dipstick. Overfill is just a more through drain and fill and you still end up with an accurate fill in the end.

 

@Acrad
All done! I performed the drain and fill, 1.74qt of ATF was drained. I filled it up with 3 bottles of Toyota WS. Opened the check valve at 116F and a little bit over .5qt came out. Performed a drive test, no leaks found.

only issue I have so far is that my ATF temp is the same as without the Setrab ATF cooler. Stays around 190f-195f via Scangauge 2. Any thoughts?

My 2018 has 17K miles

17k miles ATF on the left, new fluid on right. 2018 GX

 

Trying leaving your AT thermostatic switch pinned open. I've been running that way since early summer to no ill effects.

I may pull the pin out as we head into winter.

That is a nice setup with an additional filter.

 

Do you have any links that explain what the Thermostatic switch does? I’m curious on how it works

And thanks! And thanks for the help!

 

https://lexusgxor.com/_media/general:a760f.pdf

The element case contains wax. Just going off memory but I don't think it opens until AT temps get above 205 degrees or so. It might be higher.... not sure.

 

Hey guys... I read thru this entire thread and I think I've only see it mentioned a couple of times and wanted confirmation.... can you guys tell me the part numbers for the washers? Are you replacing all 3 washers?