I'm sure we all know that we have "lifetime" transmission fluid in the GX (Oddly enough except when you tow - so I can put a million miles on with no fluid change but if I tow I'm supposed to change it at 90k or something).

I have heard that if you run the fluid too long, you're better off not replacing it as it can cause all sorts of issues with clogs filters debris etc.

So how long is too long, and who believes in what?

 

change every 80-100k. Dont drink the kool aid

Its always good to drain and refill. a power flush can cause problems, but at that point the problems are coming soon anyways.

 

Yeah I kinda know but maybe I don't. I'm at 78k on a 2008. Think I may get it done. Diy or dealer?

 

I'm doing a drain + fill every 30k miles. Each time gets about 1/3 of the fluid exchanged, and that's good enough for me.

Chip H.

 

It's a DIY job, but it's also a bit finicky as there's a process to check the fluid level (no dipstick), and the fluid needs to be at a certain temp for this step. There's threads in here that are very detailed, give them a good read through and ask questions if you're still unsure. Doing a series of drain & fills, you should have no issues. If you have it power flushed it can dislodge deposits and you don't want that.

 

I did it myself on a 2004 and I would say just take it to a shop cause its not the most fun job, but you can DIY with some scraped up / burnt wrists.

I didn't drain from underneath, what I did was I removed one of the hoses off the trans cooler in the front and stuck it in a gallon milk jug (make a mark for the number of quarts in the pan so you dont run the pan dry), and turn on the car to drain out essentially what is in the pan (helps to shift through some of the gears also), then I would shut it off when it gets to the mark (it will start to sputter a bit) and then refill from underneath (no dipstick to fill from unless you have a 2003). the pumping from underneath is not that fun especially once the exhaust gets hot. Then you repeat until the fluid looks red, I must have run like 3-4 of those large 4+ quart bottles through it, no idea why it took that long to get full red but it did. you can also drain from underneath, but I found the trans cooler hose method to be pretty easy.

the amount of pumping and going underneath and back up and etc.. its not really worth the labor saved, I wouldn't do it again. Checking the temp at the end is easy, just follow the procedure and the lights blink... or you can just go oldschool and let it warm up some and then top off/ let the excess spill out. its not rocket science its just a pan of transmission fluid. if you are too low you will know cause it wont want to go into gear.

Also the 80-100k is just to stay on top of it and keep it perfect, if you didn;t tow or carry heavy loads you could easily go to 150k before changing it on these toyota's.

with 78k on a 2008, If I wasn't towing I wouldn't worry about it till at least 100k. unfortunately 2004 and up has no dipstick to tell the color of the fluid, but you can pop that trans cooler hose off in front of the radiator and have a quick look at the fluid color that spills out a little. Don't let a huge amount spill out or you may need to top off the trans fluid, a little bit is ok. if its got red to it then you have time left, if its dark and burnt then its time to change it for sure.

 

I'm in the camp that believes we need to pull the drain plug on the pan and refill it about every 30k. I just bought mine a couple months ago, so I just did my first change.

Service records from previous owner indicate the fluid was last changed at 58k miles and I changed it at 130k. So I'm gonna do another change in about 10k miles and call it good for 30k.

You can't really tell anything about used fluid by it's appearance or smell, but it did look horrible. I should have sent a sample off for analysis, but it shifted well enough that I wasn't worried about it. There wasn't any visible metal, and that's the most important thing.

 

You can tell A LOT about fluid by its appearance or smell. It's a huge indicator of fluid condition. My recommendation is its one service if I wasn't a tech and couldn't do it myself I'd let the dealer do. Most dealers now use a T-Tech machine or the like, which attaches at the cooler lines and uses the transmissions front pump to cycle fluid through at its normal operating pressure. The "it's got too many miles to do a flush" is kind of an old wives tale. Rule of thumb pretty much is if the trans was operating fine before the flush, it'll be fine after. If you're looking into having a flush done because you're having trans issues, chances are it won't fix it. Also forgo services that use cleaning chemicals and conditioners. I'm a firm believer that cycling only trans fluid through a trans is a safer bet. My DD is a 2006 Infiniti M35, I did the first trans flush it's ever had last year with 205k miles. It's been totally fine.

 

I let the dealer do the flush like you suggested. They used a connection at the front and flushed it out. They said it puts back in the exact amount that came out. I had a small leak so they had to top it off before doing the flush to get it at the right level. They seemed to care about doing it right. I have heard some much about the power flush that I was nervous about it. Sounds like you feel the way they did it was a good way to go. I may do it myself next time and just drain and refill like you suggested. The truck was in for the dashboard change and I just let them do it.

 

Thanks for the advice. I've never owned a car long enough to worry too much about this service (20 cars, I'm 32) but my Tacoma had 138k on it and I came close. The Toyota dealer said not to bother as it was so late to change it could cause more issues than not. Just had a really bad experience at a dealer so although I am hesitant to take it in, I'll still probably pay them to do it so I'm covered.

No issues with the transmission now but I have fallen absolutely in love with this GX and can't see getting rid of it. The wife loves it and it's my travel vehicle for work so I'll put roughly 40k miles a year on. Figure this is a cheap insurance as every other fluid in this thing has already been replaced at least once (brake fluid, coolant, diffs and xfer case twice, power steering, and so on).

Any issues with carbon in these or things to do for the engine? Oil changes have been text book at Lexus dealer per CarFax but wonder if there is anything else.

 

Some will say to leave it, some will say to change it often, some will say a power flush helps and some will say its harmful.

In my opinion a power flush is only an option if its slipping to try and nurse a few more miles out of it. I think changing the fluid every 10 years or 100k seems very reasonable. Changing it every 30k seems excessive.

The take away here is to do what YOU are comfortable with because there will be someone that loves and someone that hates every option.

 

If you're on the every 30k plan - you're changing about a third of it every 30k (the drain + fill doesn't get all of it out), so you get a net result of a full change every 90k (plus-minus-ish)

Chip H.

 

I agree 100 percent:

IMHO changing it every 30K is like having a regular transmission with Dipstick....

Whats the point of Having Sealed Transmission when it needs to changed every 30K. Also Whats the point of putting Toyota World Standard Fluid (Synthetic) If you need change it 30 K, Plus your service manual doesn't even mention the change...

(BTW it does make sense from Dealers Point of View they need to make money on all those unnecessary flushes and drain+fills)

This is what Lexus says on the maintenance forum:
https://www.clublexus.com/forums/lex...ion-fluid.html

 

There's no such thing as a sealed transmission that never requires service. All automakers that tried to go this route have abandoned it. If you want to roll the dice and believe in the marketing, go right ahead.

 

IIRC, Ford tried this with the 2nd generation Taurus. Did not go well.
By the time the damage was noticed, the car was long out of warranty, so it was a "win" from Ford's viewpoint.

Chip H.