Thanks for the details. I will have to see if the transmission line is easy to remove. I did my 2010 Camry last year at 80,000 miles by draining, filling, then removing transmission line at the cooler and running a quart out, stopping engine, and replacing a quart. This is how I have done transmissions in the past. That is just as easy as doing multiple drain and fills.I suggested trying one drain/fill and seeing how it goes because you seemed unsure about doing it with high miles. The ideal would probably be two drain/fills and a pan drop/filter change. Then you would have mostly new fluid, and could do additional drain/fills on a schedule like every 30k. If the trans is OK now, it's doubtful that new fluid will hurt it.
Some people will say that #3 changes most of the fluid at once and therefore wastes less oil. That is true, but the drain plug makes this job so simple that I'm willing to use a few more quarts for a cleaner process that doesn't disturb the cooler lines.
My experience is from a 1.8/U341E Vibe I bought with 29k. I drained the ATF first thing, and it looked like used motor oil. So I drained again and sent a sample to Blackstone. It showed aluminum was way high, so I did another drain and filter change. Then I started doing a pan drain at every oil change and sampling every other time to see if Al went down. It did trend down, everything else looked good, and the trans always worked fine. Eventually I slacked off to a drain/fill every other oil change or more until the car was totaled in a wreck.
One Drain and fill will leave a lot of old oil in the system. I don't know the actual numbers for the 6-speed transmission on my 2010 Camry as I see several listed on the internet. I am assuming 2.6 qt drain and fill and 6.7 qt total. (Please update if you have more accurate capacities).Numbers 3+4 are basically the same thing. The machine is hooked up in line, uses the tranny pump and exchanges fluid. I’ve done this on Toyota’s with 100,000 miles, zero issue. The problems tend to happen if you add a cleaner. Which I don’t.
Ive also done the drain and fills, pan drops. The problem I’ve had with those (on my own vehicles) is it’s time consuming and Toyota WS fluid tends to get dark quickly, and stay that way sometimes with the drain and fills. And some Toyota pans are a royal pain to get at a couple bolts. Plus, I’ve never seen anything close to a clogged/dirty transmission filter - but I like to get at the magnets and give them and the pan a good cleaning.
Ive also overfilled a Toyota transmission (my own) and underfilled another (my own). The overfill forced its way right past the transmission gasket, the underfill I luckily caught after a week, and nothing happened. Both shifted fine. The overfill I somehow managed to put 3/4’s-1 full quart over (still don’t know how I managed that).
I just did a drain and fill yesterday on my Avalon...fourth time now, plus a pan drop 50,000 miles ago. Fluid still doesn’t look “clean”, and it’s now at 102,000 miles. Shifts great. Always has. WS fluid just can be difficult to keep clean/red. My experience anyway.
6.7 quarts sounds about right, I will say that for some reason I cannot get 2.7 quarts out when I drain the fluid, it’s more like 2 quarts.One Drain and fill will leave a lot of old oil in the system. I don't know the actual numbers for the 6-speed transmission on my 2010 Camry as I see several listed on the internet. I am assuming 2.6 qt drain and fill and 6.7 qt total. (Please update if you have more accurate capacities).
One drain and fill yields a mix of new to old of: 39% new - 61% old
Two drain and fill yields a mix of new to old of: 63% new - 37% old
Three drain and fill yields a mix of new to old of: 77% new - 23% old
Four drain and fill yields a mix of new to old of: 86% new - 14% old
Using procedure 3 I used about 10 quarts. It wasn't until the last quart or so that the fluid came out red. So I am thinking I was in the high 90% range new fluid. Using four drain and fills is perhaps about as good: 86% vs high 90's%. The #3 pump out procedure sure is going to be a lot easier than doing three or four drain and fills though.
So here's my take. Just doing one drain and fill, unless done at short mileage intervals like 25k, helps, but 3 D&F is much better and the #3 pump out procedure is best.
And so far, I have not heard any evidence that the transmission is hurt by having a full load of new transmission fluid put in using the transmission to pump the old fluid out (#3 procedure). I guess there may be different types of machines that do the #4 fluid replacement. As mentioned in the quote, that machine appeared to not cause any problems. But apparently some machines, or perhaps the way they were operated, can cause problems.
If only 2 quarts come out from a drain, and the total capacity is 6.7 quarts, then the numbers look even worse.6.7 quarts sounds about right, I will say that for some reason I cannot get 2.7 quarts out when I drain the fluid, it’s more like 2 quarts.
I‘ll tell yeah, I am tempted to do a full exchange of all my fluid now. I just feel that at 102,000 miles now...and after several drain and fills, and a pan drop - the fluid still looks too dark for me. I know Toyota WS fluid turns dark rather quickly, but in the past (on another vehicle) I was able to get my WS fluid red, and keep it that way till I traded it in with 179,000 miles on it.
As far as tranny machines go, I haven’t seen a true “flush” machine be anything more than an exchanger. A pump is used, yes, but it’s very low pressure. The fluid from your transmission is being pumped out by it‘s own tranny pump, and the new fluid is going in by way of the machine’s pump. An exchange. Nothing more. Unless you believe that introducing 6-10 quarts of brand new fluid is a shock to the system, and the new fluid contains too many detergents that could possible dislodge something, I don’t see the difference between it and disconnecting a line and following procedure number 3. Now, if you introduce a cleaning solution into the machine - which is an option - then things would be different, however cleaning agents aren’t often used, and is an up sell at most shops.
It sounds like you did a great job changing your fluid out! You may have convinced me to do mine over again. And believe me I don’t want to. Lol.
Do you mean using the transmission to pump the old fluid out? That's #3 on my list.You forgot one option:
ATF flush using the transmission cooler lines.
I bought my former 2004 Sienna at 117K miles. Did a this method a couple of times at around 120K and D&F at 150K miles.
Transmission was good when I sold it at 250K.
I was going to do another one but I sold it before I did it.
100K for Toyota is a normal OCI for ATF.
Don't overthink it.
I've never seen anyone produce any meaningful, repeatable results of any combination of any of the choices at all. The harsh truth is there is no way for you to deduce whether anyone has any clue at all about any of the options.To those that advocate 5, I have never seen anyone produce evidence that 1-3 ever caused a documented problem. But maybe I have missed that in my internet searches.
I was hoping that there might be a professional transmission specialist on this forum that could weigh in on their experiences with vehicles coming into their shop with transmission problems and might have some insight for us. Not sure how many techs frequent this forum. I'm just a reasonably handy person (certainly no pro) looking for answers. You may be right though, that there is no hard, or even reasonable evidence regarding any of the options.I've never seen anyone produce any meaningful, repeatable results of any combination of any of the choices at all. The harsh truth is there is no way for you to deduce whether anyone has any clue at all about any of the options.