I have decided to try and change the transmission fluid on my 99 GS400.
I was hoping I could have some advice from someone who has had experience doing this. What I am expecting is to take out the bottom pan, replace the screen, clean out any metal, replace the gasket and bolt the pan right back up as the service manual instructs. Also, the book illustrates the use of a special tool to separate the pan gasket on removal. Would I really need this tool? It sounds like it's not that hard but I figured I would check before I purchase the new screen, gasket, and fluid from Lexus.

 

The tool is basically a flat wedge. Think of something like a paint scraper. Find something similar and you'll be good to go.

 

There is no need to pull the transmission pan unless you have never changed your fluid or you are having problems with your transmission. There is a metal screen in there instead of a paper filter. If fluid is changed on time, the screen will not plug up.

I pulled my pan on my first GS400, and it was a nightmare. The factory glue that holds the pan on is TOUGH to get off, and not worth the effort. I wished I'd never pulled it off.

With my second GS, all I do is flush the old stuff out and put new stuff in. I use AMSOIL UNIVERSAL TRANSMISSION FLUID instead of the Toyota stuff, and it stays clean.

If you want to pull the pan, go ahead, but I think you won't find anything bad inside, and you will have to scrape and scrape to get the gray Toyota sealer off the pan and the bottom of the transmission.

Toyota planned on 30,000 mile flushes, and never planned on pulling the pan unless there is a failure.

I thought I was doing a good thing until I pulled it down. NEVER AGAIN!

 

yeah-just drain it and refill w/2 quarts toyota t-4 through the dipstick and you're good. if the fluid is nasty repeat after driving a few times.

 

I just had my transmission and rear differential fluid changed, the car shifts so much smoothly now. I had it done at the Lexus dealership, drain and fill only

To my surprise it was only $149.95 for both transmission and differential, not bad IMO.