Confused... ATF, Dexron, Transaxle, 80w/90

[rdweninger]

Hello Subie Gurus.

1985 EA82, 3AT, Front Wheel Drive (only). Ok, so I went to change my automatic transmission fluid. Drained about 3 quarts... then refilled from the dipstick hole (Left side of motor, Driver U.S.) with Dexron II. I know there are maybe 6-7 quarts in the system... but only 3 quarts drained out... the rest is still in the 'system'. Everything is normal.

Now, I then drained the transaxle. About 1.2 quarts drained out. It actually looked like ATF. Which I thought was strange. I pulled the dipstick (right side of motor (Passenger U.S.) and the dipstick has a sticker on the top that says "use Dexron II". Thus, causing my confusion. I thought transaxles ran 80w/90 gear oil !!! At least they do in the 5-speed MT.

Can anyone confirm that the transaxle in a Front Wheel Drive 3AT does in fact use Dexron II ATF?

Thanks for your help... please !

[idosubaru]

totally normal for only part of the fluid to come about - roughly 1/3.  the rest is in the lines, radiator, torque converter, valve body, and wahtever weird stuff the 3AT has.

 

weird.  do you have an owners manual?

front diff sure seems like it should get gear oil.

 

this thread suggests regular gear oil like all the other trans front diffs:

http://www.ultimatesubaru.org/forum/topic/131560-1992-loyale-front-3at-diff-fluid-type-limited-slip/?do=findComment&comment=1120545

 

looks like gear oil coming out of this one:

http://www.ultimatesubaru.org/forum/topic/116068-front-diff-on-3at/?do=findComment&comment=990212

 

i think there's a rare failure mode where a seal can be compromised such that ATF does end up in the front diff..but I think that unlikely.  was this routine maintenance or are you tracking some slight issues?

 

ATF and gear oil mixing in 3AT's:

http://www.ultimatesubaru.org/forum/topic/8828-busted-front-diff-seal/?do=findComment&comment=74654

Edited February 19, 2013 by grossgary

[rdweninger]

This is regular maintenance. I bought the car about a year ago. GD fixed the blown head gaskets. Car only had 85,000 on it.

So I thought I should change the AT fluid and Front Diff (transaxle)fluid as the car is 28 years old and who knows if it was ever changed.

Yes, I have the original owners manual. It talks about the AT and Dexron II. And the 5-speed (80w/90) and the 4wd transaxle (80w90). The 5MT and it's transaxle share the same fluid.

I think the difference is that my car is Front Wheel drive only. But, still need verification of the Dexron II sticker on the transaxle dip stick.

Just to verify... did I get the locations correct on my original post?

[l75eya]

*edit*

I may have not conveyed what I meant to say here properly so I'll fix that for future reference

Automatics get atf
Standards get Gear oil

I'm talking specifically about the transmissions. Not the differentials.


My apologies for any confusion.
 

Edited February 20, 2013 by l75eya

[rdweninger]

Thank you I75eya for the clarification.   I just wanted to be sure the previous owner (teenage boy) didn't swap dipsticks from a different vehicle or put a sticker on there.

In my short 49 years on this planet... this is the first time I've ever put ATF into a transaxle !!!   But what came out looked like ATF, the dipstick says use ATF and the resident USMB expert says to use ATF.... so ATF it is.

By the way, the transmission fluid drained from the 3AT was absolutely black.   Everyone... change your 3AT fluid tonight !!!

[chaz345]

Now, I then drained the transaxle. About 1.2 quarts drained out. It actually looked like ATF. Which I thought was strange. I pulled the dipstick (right side of motor (Passenger U.S.) and the dipstick has a sticker on the top that says "use Dexron II". Thus, causing my confusion. I thought transaxles ran 80w/90 gear oil !!! At least they do in the 5-speed MT.

This possibly sheds some light on a strange situation I had with my 91 AWD legacy. GD was doing some work for me and found that the front diff was full of ATF. Straight ATF, not a mix of ATF and gear oil as would be the case if a seal had gone. I had never put anything in the front diff and had been running the car for 50k or so that way. And the previous owner had for who knows how long. Never could figure out why someone would have put ATF in the front diff, but if that had previously owned an older beastie line yours, maybe they thought that's how all Subies were. Edited February 19, 2013 by chaz345

[Numbchux]

I have always used 80w90 in the front diff.

 

Here's a quick look at the '88 XT FSM. In the capacities, in lists Auto trans fluid, and AT differential gear oil. And then in fluid types it says differential gear oil should be API GL-5...

 

 

 

Now, that is definitely for a 4EAT. So it's possible that the 3AT is different. But it's the same idea, front diff is just a differential and ring and pinion.....it should get Gear oil just like the rear diff or 5MT.

Edited February 19, 2013 by Numbchux

[rdweninger]

From everything I have read, and from I75eya's post, if your EA82 car has the 3AT and is front wheel drive only.... the Front Diff (transaxle) gets Dexron II.

If your EA82 car is 5MT and 4wd, the transmission and front transaxle (diff) share the same fluid and it is 80w/90.

If your EA82 car is 3AT and 4wd (Anyone ever seen one???), then the 3AT gets Dexron and the Front Diff gets 80w/90.

Numbchux... Your's is the 4EAT and your car 4wd. So, yes, you would use 80w/90 in the front diff. Is there a sticker on your front diff dipstick and is it legible?

[NorthWet]

Just to clarify (or confuse), the ATF fill/check tube is down by the distributor cap.  The final drive fill/check tube is near the pitch-stopper, high up on the side of the final drive. 

 

Dextron III in the ATF, good hypoid gear lube in the final drive.

 

If you have ATF in the final drive, it is likely 1 of 2 things:  First, someone put ATF into the final drive. Second, you have lost a seal on the input tube beteewn the tranny and final drive sections.  Both are common, but the first would be preferable to have happen.

 

I have "flushed" the system by draining the pan, refilling, then disconnecting the cooler return hose near the radiator/cooler and running the engine to drain what is in the system.  I then refill and repeat until the fluid looks relatively clean.   Might take 2 to 3 gallons.

[l75eya]

If ever in doubt, go by what the factory service manual says or a call to subaru might help clear it up (though any information regarding our cars from a dealership really does seem to be becoming quite scarce)

[Numbchux]

From everything I have read, and from I75eya's post, if your EA82 car has the 3AT and is front wheel drive only.... the Front Diff (transaxle) gets Dexron II.

If your EA82 car is 5MT and 4wd, the transmission and front transaxle (diff) share the same fluid and it is 80w/90.

If your EA82 car is 3AT and 4wd (Anyone ever seen one???), then the 3AT gets Dexron and the Front Diff gets 80w/90.

Numbchux... Your's is the 4EAT and your car 4wd. So, yes, you would use 80w/90 in the front diff. Is there a sticker on your front diff dipstick and is it legible?

 

My XT6 is a 4EAT AWD....but that page from the XT service manual refers to all XTs in '88. That includes the FWD 4EAT.

 

Also, 4WD 3ATs are not uncommon. Any non-turbo 4WD AT EA82 would be a 3-speed.

 

 

 

But, back on the topic. I do not have an owners manual for a 3AT FWD. I owned one, but never put fluid in it. I did take it apart, and mechanically, it's very similar to an EJ 4EAT. Where the front diff is just a diff. It makes absolutely no sense to me why it would have anything other than 80w90.

 

 

What I'm saying is, I'm not 100% sure what it's supposed to be used. But I would be massively shocked if it is ATF. And honestly probably believe it until I see the page in the owners manual that says so 

[idosubaru]

 I would be massively shocked if it is ATF. And honestly probably believe it until I see the page in the owners manual that says so 

Same here, exactly what I'm thinking.

 

The FSM located at the following link mentions "FWD 3AT" and lumps it right in with all the other auto transmissions maintenance items and even has a picture of it with arrows pointing to the "ATF drain plug" and "Gear Oil drain plug".  Section 1-5 page 21:

 

http://www.ch601.org/engines/files/SubaruEA82-ServiceManualPart1.pdf

[NorthWet]

Nothing magical here, folks.  The automatic transmission section takes ATF (Dextron), and the final drive takes hypoid gear oil.  Doesn't matter if 3AT (M41A, really), or 4EAT (R4AX-EL or EC8), FWD or 4WD/AWD.  I have half a dozen (at least) 4WD 3ATs, at least 3 FWD 3ATs, over half a dozen AWD 4EATs and one FWD 4EAT.  They all exist, and they all follow the rules.

 

From what I understand the "5EAT" takes a different spec of ATF, but it still is ATF in the tranny section and hypoid gear oil in the final drive section.

 

Only 2 reasons for ATF in a final drive section:  Human contamination, and mechanical contamination.

[rdweninger]

okay then... I75eya says the front diff on my 3AT FWD takes Dexron... then others say it takes 80w/90.   So I am still confused.

I put a call into the Subaru dealer... but no call back yet.  I did read the 89 FSM and there seems to be no indication that the FWD takes Dexron in the front diff.   But remember, my front diff dipstick has what appears to be a factory sticker that says Dexron. The dipstick looks exactly like the example in the 89 FSM with the 1.2 liter stamped as the fill level.  Does anyone have an 85 FSM so we can verify this?  GD... I thought you said you had an 85 FSM ?   Any help would be appreciated.  

[idosubaru]

Wh

 

okay then... I75eya says the front diff on my 3AT FWD takes Dexron... then others say it takes 80w/90.  

 

And there's an FSM link above strongly suggesting 3AT is the same as all the rest.

And your owners manual strongly suggests it's no different.

There's also no hits on internet searches, if there was something that different I doubt it would take 30 years for someone to notice and ask on the internet!!!

 

Everything points to gear oil....but the goofy dipstick....interesting.

 

The dipstick - can you post a picture of the front differential dipstick.

 

 

 

One thought comes to mind - early 3AT's could differ than later ones....seems odd but just trying to think what could be confusing here.

Edited February 20, 2013 by grossgary

[rdweninger]

I'll take some pics of the dipstick this evening when I get home.   Hopefully, it will still be daylight.

This is a rare Subaru Wagon.  1985 EA82 3AT FWD MPFI.   Yes... that's Multiport Fuel Injection.

I'm thinking of just mixing a 50/50 mixture of Dexron and 80w/90... ha !   Just kidding. 

But seriously... I want to run the correct lubricant.

I75eya.... your post was most definite on the Dexron (and I appreciate that).  Can you tell me why you are so positive?

Funny how something so simple becomes so confusing... huh?

[l75eya]

I'll admit when I'm mistaken and I should take care to notice what exactly it is I am answering when I give an answer. I was talking specifically about the transmissions themselves and not the differentials. To be honest, I wasn't even aware that the automatic transmissions contain both atf and gear oil when they are fwd only.

My mistake, I edited my first post to reflect.

rdweninger; most everybody is pointing you towards gear oil for the diff and if that is what the majority says I would definitely go with it. They are much more of the 'resident' members than me lol

[NorthWet]

I am pretty sure that I have an FSM at home for this year.  I will check when I get home.

[idosubaru]

there you go - it's gear oil...still doesn't answer why your dipstick has ATF written on it...the front diff dipstick is far different...and i don't imagine interchangeable with the ATF dipstick so i can't imagine mixing them up on installing another in it's place...still strange.

 

FWD transmissions are nearly the same transmissions as the 4WD versions...same front diff, most of the parts are the same, bellhousing, etc - they just install different shafts and rear end for the 4WD., gears and such are probably mostly the same too.

[NorthWet]

FWD transmissions are nearly the same transmissions as the 4WD versions...same front diff, most of the parts are the same, bellhousing, etc - they just install different shafts and rear end for the 4WD., gears and such are probably mostly the same too.

They hang a gear off the end of the back of the pinion shaft, use it to drive a clutch pack in the extension housing, and there ya go!

 

I just checked an 86 FSM (sorry, no 85 FSM) and an 80 FSM, and both say ATF for the tranny, gear oil for the final drive.  I went out to 2 85 GLs with 3ATs, and both had "DIFF OIL" labled on the final drive dipstick.  Pictures/scans available later, if needed.  (I need to start making bread pretty soon.)

 

The labels on the dip sticks are aluminum decals.  I suspect that either a mistake was made, or (more likely) somebody was screwing around. 

 

Hypoid gears (like the hypoid-bevel ring-and-pinion gears) have extreme pressure put at small contact patches on their gears.  They need hypoid gear lube to survive.

Edited February 20, 2013 by NorthWet