I purchased a 2008 GS 350 RWD with 235k mi, I purchased it from the original owner who has had all maintenance done to the car except one, he never had the transmission fluid changed due to the fact LEXUS told him it is a "Lifetime" fluid and does not need changing. I call BS on that, I feel every fluid needs changing. Owner told me it has mostly highway miles from one state to another. Car is in FLAWLESS condition, looks and runs like new. Full power, no dash lights, trans has zero issues. So what I want is to do a drain & fill with new filter. I will be using Amsoil Top signature WS Trans fluid. I cant use this knowing the trans is the only component that has never been serviced. What do you think/ recommend. Keep in mind this trans has zero issues. TIA

 

Just my 2cents.

Drain [no need to drop the pan and mess with filter]. Let the drained fluid reach ambient temp and purchase two times the volume and 1 crush washer. Re-install the old washer and install the drain plug. Examine the drained fluid. Expect it to be darker color. If you see other issues, stop and consult transmission tech. Fill the trans with Toyota/Lexus fluid. Drive couple off hundred miles and repeat the process, but this time use the new crush washer.

You can always choose to do more/better, but the current setup has been fine, so I would not mess with things.

Salim

 

I wanted to drop the pan to clean it and the magnets, is that a bad thing to do? I'm sure they have grown a lot of hair over the years. I could leave the filter alone

 

The previous owner was lucky to get 235k miles w/o a fluid change or transmission rebuild...maybe all highway driving can do that for you.

I also agree on "Lifetime fluid" being BS. Search the forum, there are many threads about trans fluid changes. I recall one indicating Lexus wanted to go with "lowest maintenance cost" to ownership for the 1st 100k miles. If you cancel a trans fluid change, you beat the other luxury big boys. Lexus clearly used lowest maintenance cost as a sales ploy.

I read up in this forum and decided to have my fluid "flushed" at the Lexus dealer at 100k miles. My dealer has a pressurized flush machine so you don't have to keep going back and refilling and draining. It was a little pricey (maybe $300-400), but much of the cost was the expensive genuine Toyota/Lexus transmission fluid.

Even though your new Lexus has zero trans issues, I'd recommend a flush (or multiple drain and fills) due to the mileage. Good luck.

 

I just did a drain and fill a couple of days ago. If you put it in Jack stands and leave it overnight to fully cool you will get 4 quarts out when you drain it. This way you don't have to deal with getting it up to the correct temp and opening up the overfill plug. You just put back in what you took out. I did the first one at 150k and just did the second one at 182k. I have techstream so it would not have been a problem to do it the other way but this is a simpler method for a drain and fill. I used at quart plastic paint container to catch the old fluid so I knew exactly what came out.

 

I would avoid dropping the pan at that many miles. What you can do is, do 3 drain and fills and 4th drop the pan. I wouldnt rush it! Leave about 3-5k miles in between each change. I also would stick to toyota fluid aswell, no sense in mixing different fluids to the old.

On your first fluid swap take a small sample with a napkin and inspect the fluid that comes out. If your fluid comes out clean and red, then proceed to the 2nd, 3rd etc. But, if there is a burnt smell and its super black, I would only do that first fluid swap and leave the transmission alone. A drain and fill is when you drain a certain amount and refill it with that exact same amount, add a bit extra for fluids lost in the lines.

Transmission clutches get impregnated, from there fluids and over time they get used to the viscosity. With high mileage cars and not replacing the old fluid, the fluid degrades and gets thick and gritty. Slowly wearing down the clutches in the pack. If you ever dealt with motorcycles, higher mileage motorcycles right after changing the oil, those certain oils can make the clutches slip. So youre left with adjusting the clutch or completely replacing it. In our case a full transmission rebuild or replacing it with a used one.

 

I am going to start with a simple.drain & fill, drive it for 5k mi then do another, drive it for another 5k then do a pan drop filter change and fill. Of course examine the old fluid.

 

Good idea, I can definitely do that since I dont drive the car as much, thank you. BTW what is techstream?

 

Stick with the drain and fill- DON'T flush. It's too risky, especially for a transmission with that many miles on it. Many time flushing ends up causing more problems than it fixes.

 

Techstream is the Toyota/Lexus software that the dealer uses to diagnose issues with their vehicles. You can just google it. All you need is a windows laptop or a Mac that you can load Windows in a virtual machine.

 

The good thing about our transmissions is that they are overbuilt and are similiar to the ones found in the tundra

 

Do a drain and refill, no flush. The clutch pack is used to all the "contaminants." Flushing it could make a good transmission bad, especially at these miles.