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Transmission fluid question

32K views 44 replies 12 participants last post by  tracker64 
#1 ·
I'm changing the tranny fluid on my 2004 Outback, 2.5 auto this Wednesday.
Waiting for my filter to come in that I ordered.
I'm doing that filter that hidden in the inner well.
Looks like an oil filter.
Anyhow, He told me at the parts counter to only use Subaru fluid, or my tranny will meet its end. It has 214,000 on it. But honestly shifts like new.
The fluid is medium colored, so time to change. And was always driven by and older person before me.
It's seven bucks a quart!! Geeez!
I think I need 5 quarts??
Not sure.

Isn't there any aftermarket fluid I can use that won't smoke my tranny??

I see some like adding lubeguard with their fluid, I have used it on a Ford I had. I Was surprised it worked perfect. Since that piece of crap was having trouble, it did help it.

I don't know whether the chance putting it in a Subaru.

Any advice would be helpful to my first Subaru and I truly love this car. I've only had it about a month or so now.
 
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#2 ·
nothing wrong with OEM fluid

plenty of people do fine with Valvoline MaxLife dex II/III/VI w'ever compatible.

I used a funnel with a hose to fill, level is checked while idling after moving the shifter thru each gear. Top-off very slowly - 1/2 pint at a time - the marks are not 1qt apart like engine oil dipstick.
 
#3 ·
He wants you to buy his spendy fluid.

A US 4EAT 2004 needs Dex III fluid. You can find that anywhere.
 
#5 ·
Any name brand will do. I have Valvoline Maxlife in Kaylee and Castrol in Mal, depends on sales when service needed.
 
#6 ·
Yep, pre-2006 cars call for standard Dexron III, which is probably the most common ATF available.

2006+ calls for Subaru HP fluid, which is fully synthetic, and backwards compatible with Dex III. That's what I put in our 2004, but it's not necessary. I wouldn't hesitate to use the cheapest off brand Dex III available.
 
#7 ·
That's what he told me, He said for my 2004, I had to use HP fluid??
I couldn't remember what it was called!!
Should my 2004 even take HP fluid?
I don't know what's in it currently. So I'll be mixing my new stuff with "something"...
I don't know what trans I have, still learning Subaru
 
#9 ·
if it is a 2004 US spec. standard Dextron stuff.

HP subaru stuff is what goes in US spec 2005 and newer.
 
#8 ·
Subaru says the HP fluid is back spec compatible. But it is difficult to find and expensive, so the Dex III is fine for your old 2004.

Presuming you're in the US? If so you have a 4 speed auto. There is a good DIY on fluid change here on the site.
 
#10 ·
Mine is US model. I'm in the states.
I'll just go buy the Castrol Transmax Import stuff then.
Says Import, Honda, Toyota etc? doesn't mention Subaru. Go figure.
I see my filter is located in the inner well. I'll throw 4 qts in and check.

Has anyone ever tried adding Lubeguard?
 
#11 ·
There was a time when the store shelves had bottles of labeled Dexron III. That was a GM trademark which GM, some years ago, stopped licensing to makers that met the specs.

Now, there's no bottles labelled as Dexron III. However, if you read the small print, usually on the back, it will indicate that the contents are compatible with Dexron III or meet the specs of Dexron III. It's all the same.

Many private label (e.g., store) brands, that are typically made by the major lubricant blenders and packagers, satisfy the requirements for Dexron III.

Also, many Dexron III equivalent ATFs are available in gallon-size containers, saving on the cost and waste. If you plan to change the fluid more than once (each drain-and-fill gets out only part), this might be the best to buy.

The thread mentioned earlier is http://www.subaruoutback.org/forums...anging-automatic-transmission-fluid-easy.html

Incidentally, what filter are you planning to change that's "hidden"? Have you verified the location? Most 4-speed ATs had the spin-on filter on the left side of the transmission, but a few had it in the left front fender. I though the latter were mainly 2005, but I might be wrong. Just wanted to be sure . . .
 
#13 ·
Nice link, thanks!! Mine is on the left innerwell for some reason in my 2004. I didn't remove it yet, but saw it.
I'll just grab that's Castrol Transmax then for imports.
I plan on changing it again in about 500 miles since I just got the car. I'm strange like that.
I know quite a few that like adding Lubeguard. That was on some other brand cars, but really liked it. I don't know if my Subaru will like it.

Subaru = Dextron, originally thought up by GM.
I'll be near Wal Mart and Advance tomorrow I'll just grab a Gallon of Dex3.
 
#17 ·
some folks have treated delayed engagement with Trans-X, but fresh fluid is often all that a working trans seems to need.

Our 03 also has the filter behind the battery - I wouldn't change it unless I opened the case, mixed-in the wrong fluid, or maybe if some type of 'power flush' was done.

get OEM if you change it - it looks like an oil filter but folks say it's different internally.
 
#19 ·
some folks have treated delayed engagement with Trans-X, but fresh fluid is often all that a working trans seems to need.

Our 03 also has the filter behind the battery - I wouldn't change it unless I opened the case, mixed-in the wrong fluid, or maybe if some type of flush' was done.

get OEM if you change it - it looks like an oil filter but folks say it's different internally.
It does look like an oil filter. I don't know if it's ever been done. So I figure it can't hurt to do it. I will only use a Subaru filter. Then when I drain and fill in about 500 miles, I doubt I will change the filter at that point.

OP,
I went straight for MaxLife Dex/Merc like in Eagleye's post above. It is about the only thing that holds Honda's crappy 4 and 5 speed autos together - the ones that are mated to V6s of the same millennial era as our Outbacks. Anyway, did the drain'n'fill method 3x and except for a bit of harshness on the 2-3 shift, its been good stuff. I had problems getting the gallon jugs in the Walmart stores, so I had to have them shipped at something like $24 each.
I think mine has them, if not advance does. I will use the Max Life instead of my the Castrol since you guys used it with good results. Mines shifting fine, just trying to keep it that way.
Trying to figure out how many miles apart to change it to get the tranny kind of refreshed.
 
#18 ·
OP,
I went straight for MaxLife Dex/Merc like in Eagleye's post above. It is about the only thing that holds Honda's crappy 4 and 5 speed autos together - the ones that are mated to V6s of the same millennial era as our Outbacks. Anyway, did the drain'n'fill method 3x and except for a bit of harshness on the 2-3 shift, its been good stuff. I had problems getting the gallon jugs in the Walmart stores, so I had to have them shipped at something like $24 each.
 
#21 ·
Yes that sounds like they're doing some type of flush. I don't know if I want to attempt I'm not familiar with the car.
If I have to change it two or three times pretty close together that should help.
I think going and getting an actual flush done is a couple hundred dollars it's like ridiculous.
 
#22 ·
some places use a mechanized pump, and charge big money, for the use of the contraption, and maybe some more for some magic cleaning flush juice.

others, ...just use the car's own power to do the work.
 
#28 ·
I always heard if your fluid is too far gone like burnt or really dark a flush can destroy the transmission. Could be a myth. Not sure.

I swiped my dipstick on a white paper towel and mine is a dark purple, slight brown but mostly dark purple. I am concerned about a flush or too quick of a complete change out.
Of course the readings I have done could be people beating the crap out of their cars also.
 
#29 ·
On a side not I found this. On a search here. A member asked if HP fluid was bad for our earlier cars. He emailed Subaru. Now I am livid the parts guy was forcing their HP fluid on me. Here's what I read on the forum here. Glad I found this forum. Wealth of information here with you guys!!!

What I found below......


Never mind everyone.....Subaru of America responded to my question. FWIW, here is their reply....

"Thank you for visiting the Subaru web site and for your message!

You should use ONLY the recommended fluid Dexron III in your 2003 Forester. The
other fluid you mention (ATF-HP) is for the 5-speed Automatic transmission that
is not in your vehicle.

Please see your owners manual for ATF filter replacement suggestions. It only
suggests replacing it if it is damaged or leaking. There is no in
replacing it, but it is not necessary. If you want it replaced that would be up
to you.

If you have any other questions, do not hesitate to reply to this email!"

I must say I have been very impressed with the overall customer service at Subaru Canada & Subaru of America in the last several months.
 
#31 ·
I agree with Plain OM. In they end, drain and fill is cleaner, easier, and probably nets the same amount of clean fluid being introduced into the system. 3 drain and fills gets you 85% fresh fluid which requires 3 gallons of fluid.

For fluid I personally feel the best options are Valvoline Import Multi Vehicle or Castrol Import Multi Vehicle. The Valvoline is a full synthetic, Castrol is a semi but also a very good fluid. These two fluids have viscosity's that are the same as the original DexIII specs. MaxLife has been reformulated over the years to make it compatible with the new low viscosity ATFs. The current formulation has a viscocity of 5.9 cSt @100C which is too thin in my opinion.

Here are some numbers

Traditional DexIII: 7.5cSt @100C
Subaru ATF-HP: >7.0cSt @100C (Official recommendation by Subaru for all current and past transmissions)
Valvoline IMV: 6.9cSt @100C (Full Synthetic)
Castrol IMV: 8.0cSt @100C
MaxLife MV: 5.91 cSt @100C (Full Synthetic)

Both the Castrol and the Valvoline IMV ATF's can be bought on Amazon for pretty good prices. I will be doing my next drain and fills with the Valvoline IMV.
 
#32 ·
thanks for this post, I had 2 jugs of Maxlife MV on the shelf and will trade them away for people working on things wanting newer thinner stuff,

just looking on line for product specs, and I don't see them at present, but Pennzoil makes a plain non-synthetic Dexron III,



Dex/Merc ATF - Automatic Transmission Fluid | United States

here it is in a gallon jug, lots of $12 - $30 prices online for quarts though.

https://www.pepboys.com/product/details/9332076/00010

______

I see advance sells a gallon made under the carquest label, and autozone under the STP label.
 
#33 ·
The issue with the non synthetic fluids is that they shear down very quickly and a fresh container of 7-7.5 cSt @100C DEX III may be down to 5 cST@100C within 20k miles. Obvisouly our transmissions can work in that range for a while so I wouldn't turn anyone away from using conventional ATF.

Since MaxLife is a full synthetic it is much more shear stable and will hold at 5.9 cSt@100C for much longer which actually makes it perform better over the long haul than a conventional DEXIII. The nice thing about the Valvoline Import ATF is that it starts at 7 and is full synthetic so I would expect it to still be well above 6 after 20-30k miles. Only your UOA's will tell you. This means you are getting fresh factory fluid shifting for much longer. MaxLife will be good but perform more like the tranny has been driving on fluid for 15k miles however it will perform like that and not degrade. I have heard that the Valvoline Import ATF is the old MaxLife formulation before they thinned it out to make it compatible with the LV ATF fluids.

When you also take into consideration you are mixing with old fluid which has thinned out already I think going with a higher viscosity ATF is even more important.

The Castrol Import ATF starts at 8, but since it is not synthetic it is probably susceptible to shearing and will shear down more like a regular DEXIII, but it starting higher so you can have better performance longer.

My preference would probably be Valvoline Import ATF -> Castrol Import ATF -> MaxLife -> Conventional DEXIII. Also MaxLife is an incredible value if you have a walmart near by.

Amsoil Signature Series and Redline D4 are amazing ATF fluids which are all at 7.5 cST @100C and best in class sythentics but they will cost you. These would out perform the above list. Should give you better performance and longer change intervals.
 
#34 ·
#35 ·
The first link is for the regular Valvoline DEXIII which isn't synthetic.
The second link is for the regualar Castrol DEXIII which also isn't synthetic. It starts at 7.2 cST@100C but will shear pretty quickly. I like the import version better since it starts at 8. Walmart sells the import Castrol but only in quart containers.

You can get the Valvoline Import on Amazon for $23/gallon.

If you have the Maxlife on hand then I would probably just use that. Its a great fluid but I think the Valvoline Import is better because of the higher viscosity.

You also mix all of of the valvoline products, so maybe two drain and fills with the MaxLife and then do a single drain/fill of the Import Valvoline in a year.
 
#36 ·
Possible non-sequitur. . . .

I personally like to use OE fluid for Japanese made vehicles, mostly for peace of mind and because of their affinity for transmission failure, particularly in Subaru's and Honda's . The best deal I've found is on Amazon at $8.74 a qt. I'm not a chemist. I don't know how to tell a supertech transmission fluid vs a subaru OEM so I pay for my lack of knowledge. And why is Valvoline any better than OE? No offense to any opinions here, but I think it would take a chemical engineer (one in the auto industry would work even) and molecular answer to give a proper answer as to why non-OE is better. Otherwise, it's all trial and error as to what fluid you put in your vehicle. That all being said, if Subaru says "Dex III is acceptable" than I suppose any ol Dex III would do.
 
#37 ·
All Subarus's prior to '05ish were spec'ed for DexIII (check the dipstick). You can't even buy officially licensed DexIII anymore because GM no longer will license it. Subaru introduced ATF-HP for the 05+ 5EAT and 4EAT's. Once they did that they said it was the fluid to use for the older vehicles. ATF HP is a JASO-1A fluid. JASO-1A is a ATF spec the japanese car makers came up with. It is an evolution of DexIII and will work well in the older subaru vehicles. That being said its not clear if Subaru ATF-HP is synthetic in the US market and I suspect its not. This leads to a couple of thoughts...

1. DexIII spec is very easy to meet today and almost any modern ATF fluid will meet the DexIII specificications.
2. Subaru ATF - HP was designed to be used for the newer transmissions but it is not nessecary for the older Subaru's.
3. If Subaru ATF-HP was a synthetic then I would say go for it, but it isn't (I don't think atleast) so why not find an aftermarket synthetic fluid that meets the DEX spec that can do a better job at a cheaper price.

The great part about the synthetics when it comes to ATF is shear stability. Here is a UOA from a 2008 Outback with 16,000 miles. The ATF - HP has already sheared to 5.3 cSt@100C from 7+ cSt@100C!

http://www.subaruoutback.org/forums/89-oil-fuel-discussion/17809-uoa-4eat-obw-15k.html

I own a Honda Odyssey and the Honda transmission situation has been a bumpy ride for most owners over the last decade. The research into ATF fluid for those vehicles can drive a person crazy. The Subaru's however are pretty much bullet proof if you keep some reasonable fresh DexIII in them.
 
#38 ·
A great thread. I have used MaxLife on both of my Outback 4EATs. Both improved shifting dramatically after three drain and refills including TransX in the last refill.

Now that I have read about the shear value I may change to the Valvoline Import ATF. Sadly I only have one Outback now (guardrail = 1, Subie = 0).
 
#39 · (Edited)
Used Penrite ATF FS (Australian - fully synthetic - higher shear resistance etc - recommended for later 5-6 EATs with a higher rating than dexron 111 )
when doing fluid replacement / flush in my 06 3.0R 5EAT a year ago.

As the car was imported from Japan 2nd hand with 90K miles (ex JDM) 2 years ago when I purchased it here - there was no service history with it.

As this is the 1st auto that I've owned, I didn't want to take any chances with the transmission with just a drain and refill,
considering the complexity and cost of replacing a prematurely failed 5EAT.

Drained the trans pan (3.5 liters out )
So used the trans cooler return line "off" (with clear plastic tubing attached) into pan method to drain fluid / replace fluid via dipstick tube using funnel - in 1 litre in / out increments - using engine start / stop method to pump old fluid out / top up through dipstick tube, until fluid looked clearer / newer looking.

Also moved the trans selector through RND and back while engine was running briefly each time - to help the trans flush process.

Drained / replaced 10 litres ( roughly 10 quarts)
I'm sure this didn't extract all old fluid completely but feel better / more confident than there is a higher percentage of new fluid in there compared to doing several drain / refills.

The 10 litres of Penrite synthetic ATF cost $120 here so wanted to make the best use of it.
 
#41 ·
I haven't been on the forum for days. i missed a lot of these posts.

I used the Castrol Import stuff. Hope its okay. I asked my buddy that works on Subarus, and he said it would be fine.

I changed that little filter that looks like an oil filter in the inner well. Mine ended up taking 5 1/4 quarts. Must have been from changing that filter and those lines draining.

Here's what I used on my 2004, before they switched to HP fluid in 2005.

https://shop.advanceautoparts.com/p...P?searchTerm=catrol+import+transmission+fluid


.
 
#44 ·
My thinking is that doing a single drain and fill every 15 - 20k is cheap insurance and should keep the transmission shifting well and keep the viscocity of the fluid closer to ideal. Every 30k or so if using a synthetic. You are only changing half the fluid with a single drain and fill hence the shorter interval.
 
#45 ·
I was considering doing a drain and fill in about 5000 miles.
The reason being is I had to repair that pan with JB weld, since it cracked where the drain plug threads in. I have another thread on that repair.
It sealed, but I got a new pan. So I might as well install it.
So it will get another drain and fill since I want to change that pan.

Mine took 5.5 quarts for a drain and fill.
I think that might have been because I changed that filter in the innerwell. From draining that and the lines probably drained a bit too.
Just guessing....
 
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