Transmission flush

My 2021 Tundra has just over 40,000 miles on it and I’m planning to flush the transmission. I realize this is early for a transmission service as I believe Toyota calls for it around 50,000 miles or so. I could be wrong.

I want to service the transmission now because virtually every mile my truck has driven it has had a trailer on it. I’ve picked up a new pan gasket, strainer, o rings and crush washers. I’m planning to replace all the fluid with AMSOIL OE Full synthetic. I’ve read this will help keep the temperature of the transmission lower and reduce wear.

my plan is to drain the pan, drop the pan, fill the pan. I’m curious how to get everything out of the torque converter so at this point I was planning to slightly over fill the pan, start the truck and keep adding fluid while fluid is draining from the check bolt. Ideally the used fluid from the torque converter will drain from the check bolt while I’m adding fresh oil through the fill port.

any advice is appreciated.

 

Just do 2-3 drain and fills. People report the pan bolts are known to snap.

also, have you done the rear diff since you tow so often?

 

flushes for toilets, not transmissions just do drain and fills like suggested above. Also, rear diff fluid would be a bigger concern with towing.

 

https://m.youtube.com/watch?embeds_...2NjQsMTY0NTAz&feature=emb_share&v=NUAuGmDGntY

As stated above, you should do a drain and fill (and perhaps repeat 1000 miles later or so if you're really concerned). Dropping the pan could lead to a pan bolt snapping off and heaven forbid you mess up when trying to extract it or drill it out, now you basically need a new transmission.

 

Just did a drain a fill at the same mileage, but mine is a 2019. I let the truck sit for about a week in the garage while I waxed it and waited for all fluids to get in as I did all fluid service (diffs, transfer case, PS). When I drained the pan, I got nearly 5qts out. If your able, let it sit for a bit as most on here see 3.75qts on normal drain and refill.

 

I shouldn't say transmission flush. I realize that in higher milage vehicles, that have never had a flush, you shouldn't flush the transmission because the sediment in the fluid is actually helping the transmission. I've read where people have had their transmission flushed at a shop and shortly after their transmission starts slipping.

I'm going to drain and fill, but I just don't want to drain the pan. I've watched videos of guys dropping the pan and even after draining it there is still at least a quart in the pan. The drain plug sits about 1" up into the pan so you can't drain all the fluid. I want to drain all the fluid and clean the magnets. In order to do this I'll need to drop the pan. If I've got the pan dropped and the filter is right there, why wouldn't I change the filter too? Just 4 bolts holding it in and torqued to 7ft/lb and I think the pan bolts are only torqued to 8ft/lb. I am hoping that since the vehicle is only a few years old I wont need to worry about breaking a pan bolt off. Is that a real concern on a vehicle that is only 3 years old? Is it common with the tundra?

As for the rear diff fluid, I've changed it twice and have been running amsoil severe gear.

I guess, to be safe, I could just drain the transmission and fill it. Drive it a week and repeat. Do that 5 or 6 times and I'd know that most of the fluid is fresh. I'm just concerned about mixing Amsoil OE full synthetic with Toyota WS. Is that a concern?

 

Is highly recommend just sticking with the Toyota WS fluid. That eliminates the mixing concern and know it’s a quality fluid for the trans. I have nothing against Amsoil, if fact their oils are good stuff. Just think it make your life easier if you just stick with OEM for the trans.

 

You’re way overthinking it. Do 2-3 drain and fills and leave your pan alone.

 

Noted. The pan is staying on. I’ll do 4-5 drain and fills

 

As long as they both meet toyota spec, there SHOULDNT be a problem, but why not just stick to the WS? Its not all that expensive or hard to get. I am not sure about the tundra but other toyota vehicles have sometimes been picky on the AT fluid in the past. I have heard numerous people on this forum using valvoline maxlife ATF and have not had issues.

The pan bolts would depend on where you live I guess. I am in socal so i dont think there is much concern there but if you are in a place with harse winters, I would be weary of it. Your magnets should not be that dirty at this point unless you were really tough on the tranny. You could stick an inspection camera in there and see how fuzzy the magnets are and then make a judgement call.

 

If you are not exhibiting shifting problems, maybe send a small amount of oil in for analysis, I have used Blackstone before. You will then know how your trans and fluid are doing. Don't mess with it if you KNOW its OK. Testing lets you know. You should be able to get the amount needed for testing from the drain plug, about 2-3 oz. Look here for more info: https://www.blackstone-labs.com/engine-types/transmission/

 

My understanding with the pan bolts is that they go through a steel pan and into an aluminum transmission housing, and some even protrude out the top of a lip on the transmission case. This for whatever reason is a perfect storm scenario for them to seize in there and break off rather than come out nicely. Something about dissimilar metals that I don't fully understand. I just know that drain and fills are good enough without ever taking that chance

 

Fear not, they mix just fine. I just did the double fluid change on mine with amsoil. I’ve had great luck with it in every trans I’ve put it in. It runs cooler in my RV, but I added a cooler to my tundra along with the change, so it’s cooler due to that too.

There are lots of good writeups on the change process, but here is my take. I’ve had good luck with incremental fluid changes on learning transmissions. I’m not an expert, just my experience.

I start the night before draining while on ramps. (Not level, rear low)
Next morning, add five quarts. Start the engine and move through the gears. Back it off the ramps, level (mine sits close enough to level at this point).
Get fluid up to temp, open fluid level port, close it as discharge slows. Should get about 3/4 quart back out.
Drive it at least 1000 miles, repeat until you’re satisfied. ATF looked new to me after two changes.

BTW, You want the fuel efficient amsoil ATF. I used signature series, but all grades of that type meet the Toyota WS spec.
https://amsoilcontent.com/ams/lit/databulletins/g3110.pdf

 

At that milage I would do like others have said. Drain and fill. And I would just stick to WS since you are doing it early and will probably do it again at another 40k. It's been discussed to death here and it's pretty much a waste of money. All these boutique oils can not and will not prove that their oil is that much better in the long run. But in the ends it's your money not mine.

 

I have dropped the pan on mine, I wasn't planning to but I broke a bolt trying to be proactive changing them out. If you drop the pan and pull the filter you end up getting a little over 6qts out. Its dependant on where you live on whether or not your bolts will be snapping or not. If you add a cooler you can flush the system using the cooler hoses but other than that just doing drain and fills is sufficient, if you are worried about it I'd add a cooler, then you'll know you're not cooking the fluid pulling a trailer.
https://www.tundras.com/threads/my-transmission-pan-adventure.110777/

 

One small item I'd like to attempt to offer is when something "Meets Spec". Any fluid that has been approved to a vehicle manufacturer specifications will ALWAYS have a license # with it. You will never, ever see a fluid that can replace ATF WS with a license # included. If you look at the Amsoil example above you will see a plethora of platforms it can be used on with many if not most having a license # with them. You can be rest assured it meets all requirements if said license # is included. If not, then by all means you on your own. Also, in the Amsoil spec sheet, the Amsoil Multi-Vehicle fluid somehow is compatible with all Toyota Type T, T-II, T-III, T-IV fluids at the same time even though this is flat out impossible. Every Toyota manual states a particular vehicles fluid requirements. For decades Toyota only allowed their coolant to be used in Toyota engines while every coolant out there stated they were compatible. We all now know the silicate level of these "mostly" GM coolant standard coolants beat the shat out of Toyota engines yet the jugs all said compatible but without ever posting a license #. Every coolant manufacturer now has Toyota approved coolants and thus your manual states "SIMILAR" when addressing a particular fluid. Almost all Toyota fluids have this added in their manual for virtually every fluid they offer. The one exception being Toyota ATF WS. I realize that your cousins sisters uncles turtle ran some fluid and never had a problem. My granddad smoked till he was 96 so I guess that proves smoking is good for you. Will running Amsoil in your transmission cause and issue, I don't know. But there are an insane number of 500K+ Toyota's that ran only ATF WS for it to be some kind of substandard fluid. To the OP, at 40K miles go ahead and flush if that's what's easiest for you. 40K is nothing so the flushing issues everyone likes to repeat cause they read somewhere are not relevant yet. People need to realize that everyone does not have access or the ability to do a drain& fill at home. More impressed to see your more interested in doing early preventative maintenance which is fantastic. When your truck hits 250K call me before you sell.

 

While you're under there remove one pan bolt at a time and apply a coat of thread lubricant or anti seize before re installing. I did this to my 21 before I hit 500 miles. Unless you live in the rust belt you should have no problems removing the bolts.

I tow around 40% of the time and did my first drain and fill at ~ 22,000 miles and will continue to do so every 10k as long as I'm towing this much.

A trick I learned on buying WS ATF: Go online and find a dealer selling at a reduced price and ask your dealer if they will match the price. My dealer even beat the best price selling me WS for less than $8.00 a quart in the end.

 

Thermostat pinned open...I run 155-175 no matter what. I don't tow.

I use Valvoline Maxlife ATF for all my drain and fills. WS=WS.

given those 2 variables, have I extended the life of my trans or no?

I've done 2 drain & fills over the truck's 86k miles. next one is in March.

 

You have a 2021 and tow daily. I would consider adding the transmission cooler that Toyota removed from the 19+ models. Having the external cooler lines allows you to change all of the fluid at once. There is a method to let the fluid drain from the line going to the cooler and fill with the one going back to the transmission then. Problem solved all the way around. And no, I wouldn't bother dropping the pan.

 

If you are going Amsoil, go signature series. I did a full exchange with amsoil and it shifts smoother, I also have a aux cooler in line with the factory cooler, I also added a magnetic filter as well.

 

I did drain and fills on my 09. A couple around the 40-50k mark, maybe one more close to 100k. Shifted like brand new at 113k and 13 years when I traded it. Never a hiccup.

 

I think you're perfectly safe to do a flush if you'd like, however I'm glad to hear your changed your mind about removing the pan. I also chose to keep mine on as I didn't want to deal with extracting broken bolts.

I did a full DIY fluid exchange (or flush if you'd like) by starting the truck and allowing the transmission to pump out ~3 quarts at a time from the cooler line, then refilling the pan each time. This procedure safely flushes out all the old fluid without excessive pressure. I followed the procedure shown in this video ( https://youtu.be/cB8MdGgwg68?si=1ykZPiC0KSFj8UoX ) and it went very smoothly. I used Aisin branded WS fluid as Aisin built the transmission. I think you would be 100% fine to use Amsoil so long as it meets spec for WS fluid....which it does. I believe I bought and used all 14 quarts (It hold just under 12 total), so I flushed out a little extra new stuff. It was very easy to see the color change when all the old fluid was out.

Drain and refills and absolutely fine, but there's no need to worry about doing a full fluid exchange at that mileage. I did my very first one at 92k miles, and the truck drove better than ever afterwards. Since then I towed around 7k pounds in car and trailer for nearly 16 hours round trip and never saw over 205 degrees pan temp. No harm done.

 

Been thinking about adding an aux cooler. Where'd you mount yours? What are your temps?

 

What a PIA. I miss the days of dropping the pan, swapping the filter, and then just adding fluid until it's full.

 

Haha yeah I'm afraid those days are long behind us. Hell, even in my G8 the 6L80e likes to be overfilled by about 3/4 of a quart (although I do have a high stall converter). The process is the same though with the fill and fluid level check hole. It's really not a bad process, but most people just don't like to take the time to figure it out, or they'd just rather pay someone.

 

I don't have the patience to deal with that. $350 and Toyota will do it and I can drink coffee and take a nap while I wait. Other fluids I've got.

 

I ended up getting the genuine cooling systems kit second hand for a great deal, and I honestly don’t monitor it, I figure with synthetic fluid and redundant coolers I’m sure it’s running much cooler

 

I recently did a transmission service.
I also changed out the pan gasket and filter (strainer).
I cut the filter open , and after 81,000 miles it was extremely clean , and i now realize it would most likely last the life of the transmission as toyota says it does.
In my opinion, id leave the gasket and filter alone and either do a few drain and fills to gradually work in your Amsoil , or if you want to exchange all the fluid out in 1 shot do the oil cooler method.
Amsoil is a WS rated oil and its ok if it mixes with the OE oil.

link to my filter cut open here...


https://www.tundras.com/threads/transmission-filter-cut-open-pics-strainer.135128/

 

MILK = MILK

 

I don’t get the milk thing