How much ATF should be changed at main service?
 

I'm taking my 2013 GT86 AT in for its 6-year main service at a dealership tomorrow. In the quote they specified 2L of auto transmission fluid. I asked them if that was correct, as it sounded very little compared to the 7.5L total capacity. They confirmed that it was standard procedure to change only 2L.

Does this sound right to you guys?

They are probably just doing a drain and fill, not a full flush with that little fluid

I'm not sure what is specified, but personally I'd want to do a full 7L, which is what I do each time I change my ATF. It is more work since you can only do about 2L at a time and must row the gears to get fluid exchange to occur. They can pressure flush it, but I advise against that as it can damage the internals. Since your car is 6 years old and is out of warranty, you should consider doing the service yourself at home. I made a thread in the DIY forum on how to do this, it's a bit time consuming but pretty straightforward.

http://www.ft86club.com/forums/showthread.php?t=8374

Page 140-142 of the PDF linked above. 2L is spec for a standard drain and fill service.

I think a 2L drain and fill every 15-20k miles would probably be fine. At 60-80k a full 7.5L drain and fill (but specifically not a flush) would be advised.
@ZionsWrath @theadmiral976

3-4 drain and fills, NOT a flush

True, if you want to be unnecessarily technical about it.

Except that being technical in this situation is entirely necessary. Flushing the transmission is used by many shops and other people in the industry to imply forcefully extracting transmission fluid followed by a complete fill. Some transmissions can handle this procedure, assuming it is done correctly. But there is plenty of evidence, anecdotal and systematic, that power flushing can lead to additional damage and even destruction of many transmissions.

In general, and especially for low mileage (under 200k) transmissions, the risk of sludge being left behind with just a drain and fill is way lower than the risk of damage to the transmission with a power/vacuum flush. Therefore, lots of shops and other professionals strongly recommend sequential drain and fills, either all at once or over time (say, 2 L once every 20-30k).

Definition of Flush - “cause (a liquid) to flow through something”
I am causing 7.5L (of ATF) to flow through my transmission in order to flush it.

You are correct when using Merriam-Webster and even probably in many other industries and professions. Unfortunately, the auto repair industry has co-opted that word to indicate use of a power/vacuum-assisted machine that (typically) hooks up to the transmission cooler lines. Lots of people assume that this is what is happening when you ask for a "transmission flush service." Since that service can harm many transmissions, it is important to clarify this for people, especially since many people use forums like this to learn about stuff. The last thing any of us want is for someone to harm their car because they misunderstood something that isn't entirely obvious (as it uses what amounts to an industry colloquialism).

Ok corrected it. :cheers:

Necroing an old thread. I have ~50K miles on my FR-S in 11 years, runs great. Planning on changing the AT fluid at 60K.
I also had a 2014 Ford Escape that I changed, (3 x 4 qts drop and fill) the AT fluid (9 qts capacity) at 70K miles and planned to do it again at ~130K. I purchased 3 more gals on sale of https://shop.valvolineglobal.com/pro...smission-fluid
The Escape got totaled and we replaced it with a 2024 Hyundai Tucson.
I used the Valvoline Multi-Vehicle ATF in the Escape with no problems. According to its product spec sheet it is ok for all Scions. https://sharena21.springcm.com/Publi...0-ac162d889bd3
I know that the FR-S ATF capacity is 7.9 qts, and the shop manual states to do a 2 qts. drop and fill.
Has anyone that has done this got out more then 2 qts. a drop?

The attached excel Partial Drain calculator was posted on the Bob is the oil guy forum a few years ago. Attachment 224007
If you plug in 7.9 qts in the Total Fluid box and 2 qts in the Partial Drain and Refill Amount box it calculates it would take 16 qts of new fluid to reach 90% new fluid. How accurate is this calculator???

I have only used 6-7qts max when doing drain and fill 3x for each change

Thanks for the info. I have 12 qts of the Valvoline Multi-Vehicle ATF. I could do 5-6X drop and fills if you can get only ~2 qts out a drop.
Here's a screen shot of the partial drain helper:
Attachment 224016