Transmission flush needed? (1 Viewer)

[drowzyGX]

Hey Y’all,

I didn’t think this would be such a pain to get done, but, alas, here I am asking for help.

I’ve called 5 dealerships around me, and all of them refuse to change the transmission fluid, insisting it’s a closed system and Lexus never intended it to be serviced.

Everything I’ve read indicates this job has a really specific process to flush all the fluid and replace it - that’s why I wanted to go to a dealership.

Where do y’all get this done (for those who don’t DIY)? Am I crazy for asking the dealerships near me about this? I thought the FSM has a procedure for this job…

 

[Rednexus]

It's not a difficult job for any shop to do, just kind of tedious. I would find an independent Toyota mechanic or independent transmission shop who works on Toyotas who knows how to do it. Frankly, as far as DIY jobs go, I'd put it in the "easy but messy" category - if you can change your own oil, you can do it yourself. The dealers are full of BS though - all fluid needs to be changed, "lifetime" means 60-90K and most of us want to drive our GX's to 300K.

Wherever you get it done, make sure they drop the pan, clean out the sediment, and replace the filter/gasket. Flushes can go wrong if the pan is not dropped and the flush stirs up all of the sediment in the pan.

After the pan is cleaned, it's a simple process of disconnecting the transmission lines at the cooler (behind the grille), starting the engine, putting the trans through all the gears, allowing it to pump out 2 quarts of fluid, then putting 2 quarts back into the transmission (either through the fill plug on the transmission or the cooler return line behind the grille). Repeat that 7-8 times until new fluid comes out, then check the transmission fluid level at the pan using the FSM procedure (which only requires a paperclip at the OBDII port to jump some pins, then allowing the trans to get to 105 degrees), and top off if necessary.

You can DIY this for around $120 using MaxLife ATF and a $20 gasket/filter kit. Maybe another $20 for plastic tubing and hose barbs to connect everything.

 

[Mr Chuck Norris]

Really? That's... Odd.

The GX470 factory maintenance manual calls for transmission fluid to be replaced every 60k miles for "Driving While Towing" and my Lexus dealer was happy to do it. Try pointing that out to them, and try also calling Toyota dealers.

Edit: Also, try saying that you tow with your GX if they balk at it. But really you should at least be able to find a Toyota dealer who will be willing to take your money and do the work.

 

[drowzyGX]

Yeah - they all gave me the same info: “it’s a sealed system and not meant to be serviced”. One even went so far as to say the only time they’ve flushed a transmission they made the customer sign a waiver for any potential damage that results. I don’t know. Maybe they just don’t want to do the job, and this is their way of saying no without saying no.

While I feel more than comfortable changing my own oil, this is quite a step up from that based on the procedures I’ve read online. I don’t have tech stream, and the procedure to get the truck in temp check mode and then do the full flush is not something I want to learn by myself on my daily driver. If I screw up badly, that’s a couple grand.

There’s a detailed thread on the 100 series page here on this procedure, but it’s pretty mixed on whether or not to drop the pan and clean it. All in all, this is one I’ll happily leave to the professionals. Transmission is too important and expensive for me to learn on.

 

[Rednexus]

You can use an OBDII adapter and app like Torque Pro as well and skip TechStream to check transmission temperature - which is what I did the last time I checked the fluid level (after installing an aftermarket cooler). There are YouTube videos on the flush too. The only way it could really be screwed up is if you were to take out way more fluid than you put in, didn't check the level at the end, and then drove around. So as long as you keep up with the measuring (I used a paint bucket to measure two quarts out, then measured and put two quarts back in), and do a final level check at the end with the trans at 105F, you should be fine.

But if you do want to leave it to a professional, just find an independent shop who understands what it needs and has done it before. The pan drop itself is a minor extra effort (<1 hour), lets you (or the tech) inspect the pan for junk/metal pieces/gunk, and clean it before re-installing. I personally don't see how anything "bad" could happen from dropping the plan, but NOT dropping the pan will definitely keep some gunk in your system, and allow your new fluid to stir it back up and recirculate it (thereby contaminating your new fluid). For the minor cost of a pan drop, it's worth it to get your system totally clean, IMO. My trans at 135K, when I flushed it, had a nice layer of gunk in the pan but no metal pieces.

 

[Mr Chuck Norris]

The funny thing is that it's not at all a "sealed" unit... There is a drain plug, fill plug, and check plug for this exact purpose. The procedure is outlined in the FSM. It's not rocket surgery. Just messy and requires a tool to monitor trans temperature.

 

[drowzyGX]

Thank you both for the info. I’ll try to call around some of the well-reviewed indy toyota / lexus shops and see what I find. Really wanted to do this one at the dealer because it typically comes with some basic warranty, and they’re a bit (in my experience) easier to work with on warranty claims than an Indy shop.

Maybe I’ll give this one a try on my own. If it’s really that idiot-proof. Maybe I can convince a friend or someone local to help out in exchange for $$ / beer and food. Just nervous to mess with such an important component on my own.

 

[Daskoff]

I went to a Toyota dealer near me and they did the flush for about $350. It is a sealed system and they never dropped the pan since there is no 'real" filter media except a screen. They used about 12 quarts of WSATF Puresyn ATF. They said that they used more than required to do the flush which includes flushing the converter as well. My truck is a 2012 model.

 

[Rednexus]

Regarding the "sealing", I'm pretty sure the transmission still has a vent (like a diff), so some amount of outside air can enter/leave it, and it's not a truly sealed unit. The gunk at the bottom of the pan is due to the normal wear of clutch packs and metal within the transmission, rather than some external source. Quite a bit of that will accumulate over 100+K on a vehicle and it's totally normal - my preference is always to get rid of it when dropping the pan . There is a screen, mine was totally clean but I went ahead and replaced it because the screen came with the pan gasket.

If you DIY you will get some trans fluid on you - and on whatever surface you are working on - so that's always the risk. It's also kind of a PITA to get the fluid in through the fill port on the back of the trans (doable with the engine running but you need to squeeze it up there), or in through the return line from the cooler (I used a funnel and it flowed very, very slowly). None of this is hard, just tedious/slow/messy and hard to mess up, which is why it's a good DIY job.

 

[Mr Chuck Norris]

For reference, I attached the relevant pages of the FSM. I always forget about the jumper/blinking light method for checking the temp!

You can do this with normal tools and no techstream or anything electronic.

 

[Mr Chuck Norris]

There is the debate of how much fluid will gravity drain versus the amount that will remain in the trans and torque converter... Anyone dealt with that directly?

 

[Rednexus]

There is the debate of how much fluid will gravity drain versus the amount that will remain in the trans and torque converter... Anyone dealt with that directly?

The FSM method linked above seems to be a bit different than the flush method I did from the cooler under the hood. The trans pump should constantly recirculate fluid from the trans inners and TC to the cooler, then back to the pan. So if the pan is dropped/cleaned, and refilled, all of the fluid coming into it will be dirty stuff. Diverting the old fluid it at the cooler, then adding new fluid to the return line, keeps it from mixing with the new fluid. I was getting fresh fluid around Quart 14 or 15 when I did it that way, so it seems like that would have covered the TC as well.

Perhaps if the flush method is not in the FSM....that would explain why some dealers don't/won't do it.

 

[midwestgxer]

I have done the DIY procedure using the trans cooler lines on a couple different gen3 4Runners and 2 GX's. It's pretty straightforward. Put the same amount in as you replace and follow the procedure to check the level and top off if needed. Easiest way I've found is using the most easily accessible trans cooler hose for pumping the fluid out, and a drill operated pump to pump fluid back in though the trans fill plug. Use buckets with graduate lines to keep track of fluid removed and fluid added.

And technically, this is a "full fluid replacement" not a flush. Pretty sure a flush uses pressure to force fluid through.

 

[HomersCanyonero]

I would like to point out that the 2003 and 2004 gx470s did have a transmission fluid replacement schedule.

I believe in 2005+ is when the sealed transmission came into play.

I have a 2003 and it has a transmission dip stick to check the fluid so mine is clearly not sealed.

Someone correct me as to the 2004 being sealed or not. Model year might be the reason for some confusion on this topic.

 

[jiggletits]

I find the transmission service to be well worth the $180 they charge at the dealership. **** crawling around making that mess on the ground, and still spending $100 on fluid and filter. Plus they are quick at getting the full fluid change without doing a "flush". I've always heard you should never "flush" a Toyota transmission. Especially the newer sealed ones with lifetime fluid.

 

[drowzyGX]

I find the transmission service to be well worth the $180 they charge at the dealership. f*** crawling around making that mess on the ground, and still spending $100 on fluid and filter. Plus they are quick at getting the full fluid change without doing a "flush". I've always heard you should never "flush" a Toyota transmission. Especially the newer sealed ones with lifetime fluid.

where did you get a full flush for $180?

Even on the other forum posts about this, the cheapest I saw anyone pay was $400. Found 1 dealer about an hour from me that charges $500.

I’m weighing doing this one myself. Convinced my pops to let me use his garage and get his help as labor.

 

[jiggletits]

Stevinson Toyota West. This was on my Tundra and it’s the sealed 6 spd trans.

 

[Rednexus]

Stevinson Toyota West. This was on my Tundra and it’s the sealed 6 spd trans.

You sure they are getting all of the fluid or just doing the basic drain and fill of the pan only and just replacing a few quarts? The WS fluid is $10 a quart so the fluid cost alone would be ~$130, leaving only $50 for labor. If so, that's an absolute bargain, although they probably are leaving gunk in the pan by not dropping it.

For average stealership prices, the fluid with the fat markup would be $200 or so, plus another 1-2 hours of labor, so $300-500 does not seem out of the question.

 

[jiggletits]

You sure they are getting all of the fluid or just doing the basic drain and fill of the pan only and just replacing a few quarts? The WS fluid is $10 a quart so the fluid cost alone would be ~$130, leaving only $50 for labor. If so, that's an absolute bargain, although they probably are leaving gunk in the pan by not dropping it.

For average stealership prices, the fluid with the fat markup would be $200 or so, plus another 1-2 hours of labor, so $300-500 does not seem out of the question.

It was in 2019 for what that’s worth. Full drain.

 

[greenscobie86]

I have a 2003 and it has a transmission dip stick to check the fluid so mine is clearly not sealed.

Someone correct me as to the 2004 being sealed or not. Model year might be the reason for some confusion on this topic.

My 2004 has no dipstick. I replaced my pan filter and trans fluid with Toyota ATF and used techstream to monitor the temps before setting the correct fluid level. Messy but totally easy.