"High performance" AT fluid

Is anyone here aware of a "high performance" transmission fluid that supposedly is needed for my 2005 Legacy GT automatic tranny? The dealer tells me it's $175 for the service.

while the Subaru 5EAT fluid isn't necessarily cheap, their service *might* be a trans flush which is more robust of a service outside of a drain and fill.

 

Drain and fill is usually about 4 quarts or so, full flush is around 12 quarts I believe.

Yes and it's a hard fluid to find elsewhere. The two ATF fluid types listed in the owner's manual aside from the Subaru brand weren't at any auto supply store I tried. I ended up going with Amsoil, and am very satisfied.

 

From what I've read, all of the above ATF options have been tried with good success. I don't think there's any significant data on them having been analyzed and compared on our 5eat trannys. Hell there's even a guys who accidentally put in DexIII and had no problems (not saying you should).

 

Going to the dealer is the most expensive way to do almost anything, period.

You guys had it right. They did a "flush", which allegedly needed 16 quarts of fluid. I knew the dealer (Harte Subaru in Hartford) was the expensive way to go, but they didn't say anything about the cost of that service in the initial estimate.

I don't know if you're up for it, but if you can have your mechanic just drain the 4 quarts that will come out of the tranny pan every time you do an oil change, you will be fine. Tranny flushes are expensive and unnecessary if you just maintain it in the aforementioned way. There is also some weird thing that occasionally happens to ATs where when a flush is done it actually messes up the tranny. Someone just posted with that exact issue again.

 

You could just stockpile the atf fluid of your choice in a corner in your garage and bring a gallon with you each time you got to get an oil change. Easy as pie.

You'll need Castrol Transmax J, I believe.

You'll need Castrol Transmax J, I believe.

 

I wish I had the manual in front of me, but you can look it up!

Options are:

Subaru ATF for 5eat

Castrol Transmax J

[some other brand in the owner's manual in your glove compartment

Amsoil ATF

 

Subaru surely contracts through one of the two in the owner's manual, or a different company also making what is basically the same thing. Amsoil is the unique one, being full synthetic. It moves easier when the tranny is still cold, and theoretically it won't break down as easily at high temps, which you simply won't see if you don't start modifying, as it does a decent job stock.

I investigated this 2 years ago (see this post) and found that the two non-Subaru brands mentioned in my '05 owner's manual were not readily available. I purchased a case of the OE (Idemitsu ATF HP) fluid when one of the vendors was offering 15% off or free shipping or something and had a local shop do a full flush. What does the manual for later model 5EATs say to use?

 

When I had my 5EAT rebuilt by IPT the local shop used MOTUL ATF...

http://ep.yimg.com/ip/I/yhst-63999469945013_2055_35024073

 

 

I have a supply of Castrol Import Multi Vehicle ATF I use for regular drain and fills...

http://www.castrol.com/assets/bp_internet/castrol/castrol_usa/STAGING/local_assets/images/products/08Import_MV_ATF282_648.jpg

 

I see IPT just started offering their own branded ATF...

http://www.importperformancetrans.com/images/inventory/IMG_0815good.jpg

Per the IPT-branded stuff, IPT has told me repeatedly they only use Amsoil on Japanese and American cars, so there is a possibility it is that. Then again, people say a lot of things in the car world, a lot of it being smoke and mirrors.

anyone use the mobile 1 fully synthetic? it says for use on all auto transmissions

The manual quotes the following ATF fluids:

-Idemitsu: Aporoil ATF HP (this is the OEM stuff)

-Castrol Transmax J

-Pennzoil-Quaker State: Pennzoil ATF-J

anyone use the mobile 1 fully synthetic? it says for use on all auto transmissions

A lot of ATF products will say this and a lot of owners ask this very same question. The answer has always been the same: we do not know. It is not on the recommended list. The transmission, if it fails, costs at least 4-5 grand to replace. If you want to be the guinnea pig and let us know how your clutchpacks are doing on OEM that is not approved, go ahead. I am personally not gambling with ATF that:

-is not on the list

-has not been proven to work

on a unit that costs several thousand dollars, just to save twenty bucks. If you're asking because you like Mobil 1 products and think they are superior, then know that the OEM stuff is just about the best there is and so far Amsoil has proven the only better alternative. If you want better than OEM stuff, then go with Amsoil and call it a day.

 

Even the OEM Subaru/Idemitsu 4-speed automatic ATF is NOT recommended in the 5-speed automatic ... The automatic is a JATCO unit, and they are known for not accepting just about any off the shelf stuff.

So I can get the Amsoil ATF at my local Napa. How much should I buy to do a drain and refill the next time I do an oil change? Also, is there a walkthru available for changing 5EAT cars like there is for the MT's?

You need to do a flush in order to replace ALL of the old fluid with new, since you are mixing brands. It is not going to be cheap and the question that comes to mind is: are you modded? do you race the car? otherwise drive it hard? I am at Stage 2 still running OEM stuff and it is holding up just fine.

So I can get the Amsoil ATF at my local Napa. How much should I buy to do a drain and refill the next time I do an oil change? Also, is there a walkthru available for changing 5EAT cars like there is for the MT's?

 

What I did (successfully) is I pulled the AT pan plug, which drops about 4 quarts. This is when I had only OEM in it. Then I added 4 quarts of Amsoil (well actually a hair less, add a little less then check it when it's running, then add more if you need it. So I ran it a little, then pulled the plug again and did another 4-out 4-in. There really shouldn't be an issue if some OEM is left in there.

 

People on this site will argue about oil for hundreds of posts. There is a point, however, where it just doesn't really matter as much as people suggest. My point is you will go insane trying to do oil "perfectly," when all you really need oil to do is make metal thingies slide against each other without grinding away a lot of material or getting too hot.

 

Now about flushes... many people have and will do them without any problems. But I never will, and I even still have a little oem atf floating around (causing zero issue) because the sex wagon doesn't have any issue with it. If g-d forbid I did a flush and something got knocked loose and my baby didn't shift perfectly after that, I would be very unhappy.

From what I've been told, Temp is the biggest enemy.

Tranny Cooler FTW.

I have a tranny cooler on my car, I have noticed shifting to be more consistent. I may just do amzoil, I am going to order some motor oil tonight or tomorrow.

Which tranny cooler do you have? I'm gong stage II very shortly, and I don't want to cook my transmission

I just have one from the local parts store. Its fine for me, because I am not in a cold climate, so I don't have to worry about my car warming up first. I think there is a true cool that lets cold fluid pass around the cooling fins, and once it warms up it goes into the tub and fins to get cool. Do a search there is a huge debate about tranny coolers. I just got the biggest one they had at the store....lol but I Also tow with my car, and have parts in my garage for stage 2

From what I've read, all of the above ATF options have been tried with good success. I don't think there's any significant data on them having been analyzed and compared on our 5eat trannys. Hell there's even a guys who accidentally put in DexIII and had no problems (not saying you should).

 

if you want to know.... just get a log and you'll see that the ATF will get too hot compared to SUBARU ATF. I got the same problem and since that in saudi arabia is a hot country, I noticed it directly and specially if I'm driving in the highways.

 

the boiling point of the DexIII is less than SUBARU ATF.

also it is thicker which means that it cannot lubricate the tiney spaces between the 5EAT parts that good.

 

if you do that and you use it for around 5000 miles, you'll notice that the shifting is too slow and there will be a large lag time between shifts.

 

to solve it, you'll need to flush and then clear the TCU data and then do a learning. all of this cannot be done if you don't have SUBARU SELECT MONITOR III.

 

I hope it is clear for you all

If it ain't broke, don't fix it. Run OEM stuff and call it a day.

if it ain't broke, don't fix it. Run oem stuff and call it a day.

 

+1

If it ain't broke, don't fix it. Run OEM stuff and call it a day.

normally I would agree with you, however, I do tow with my car, and I wanted a HD transmission fluid. I have the cooler, but if I can get a transmission fluid that can handle more heat that would be best

^You tow and you are also at Stage 1. You fall out of the typical use so if I were you I'd also be looking at a better ATF.

^You tow and you are also at Stage 1. You fall out of the typical use so if I were you I'd also be looking at a better ATF.

and I have stage 2 parts in the garage:cool: