DIY: Gen 4 3.6R ATF Drain and Fill

[AltaBrig]

Yesterday, I changed several fluids due to the fact that my OB recently passed 35K miles. I decided to post a pictorial DIY for this easy $ saving fluid change.

Oil and new Washer:
4 Quarts ATF type HP (Idemitsu makes it for Subaru)
Crush Washer (Part #11126AA050)



Tools:
Ratchet
14mm Socket
Torque Wrench (18lb/ft)
Measured Receptacle (If you want to know how much ATF drained out)
Gloves
Rag



Remove 14mm Drain Plug with receptacle in place. Normally I would use an oil container, but the first couple of changes I want to make sure I know how much fluid is being drained.



Apologies for the blurry pics
About 4 quarts + 8-10 ounces drained out (more on that later).

Remember the new crush washer. I used 18lb/ft torque which was about a quarter turn past finger tight.



Add 4 quarts ATF type HP through the dipstick tube. The Rhino Super Funnel works perfect.



Nice fresh red ATF. Much better than the chocolate colored stuff that came out.



Almost done.

Check the drain. Run the car through the gears. Check the stick with the car running (in the COLD L to H range?) Good. Take the vehicle out and get the ATF up to temp. Run it through the gears. Check the stick with the car running (in the HOT L to H range?) Good. The fluid is within the acceptable range.

Check the fluid repeatedly while Cold and Hot for several days to make sure you have a stable level after the fluid has worked through Tranny.

Here is mine after running Hot. I checked it twice today after running it in the morning and this afternoon. Same level just below the High HOT hash mark. I will watch it for a few more days.





My ATF change was a bit more of an ordeal than the pictorial illustrates due to the fact that I had to pump out about 3/4 quart just to set a baseline within the hash marks before the drain and fill.

The factory (or a dealer at the time of a recall/warranty service) overfilled my transmission by a quart. I took it for granted that it would be ok (my mistake), after the dealer and the alignment techs checked the ok box on ATF fluid color and level 4 times! Either it came too full from Indiana or a dealership tech added an extra quart when it was in for a recall/warranty issue. This is why I try to do most routine maintenance myself.

I recognized the overfill by checking my stick (car hot and running after going through all the gears) my fluid level was 3/8" above the hot high hash with the fluid hot and 1/4" below the hot high hash with the car started (running) and the fluid cold. No bueno. I am hoping the Tranny life has not been compromised by 35K of driving with too much ATF. I have no idea what strains that put on the seals, gears, etc.

Posted on the issue in Problems and Maintenance: ATF dipsteck level TOO HIGH

In order to set a baseline that still touched the High Hot mark, I pumped out 24 oz of ATF through the dipstick tube and the level was still just above the cold marks with the fluid cold (car running after going through the gears.)

I got 4 quarts + another 8 to 10 ounces out on the drain and fill. The stuff came out very brown, not even reddish in the least. Added to the 24 ounces that extra 8 brings me to a quart over. Now when did that happen?

Moral: Don't be a dipstick. Check your levels before you drive of the dealer lot new car or not.


At last, I have the dipstick fluid level in between the cold high and low when the fluid is cold and between the hot high and low with the fluid hot.

I am not sure if I will just do the 4 quart drain and fill on a much shorter interval ~15K or if I should cycle my ATF through over the next month by doing three more changes - one every couple of weeks. That fluid was pretty dark, but it did not smell burnt IMO. Sure didn't have the slightest bit of red tint left. That said, I have put in 35K with lots of hard mountain miles on the tranny and should have changed the fluid sooner.

[WiscoOB]

Excellent write up! Let us know what the fluid looks like on your next change if possible.

[AWDFTW]

Moved to DIY forum.

[AltaBrig]

^ Thanks. Will do. I am not sure if I should wait 15K or do the sucessive changes like a member suggested in Brucey's original ATF thread? The stuff was too dark for ATF IMHO.

This obviously refers to different car and AT, but the idea is the same about cycling (flushing) new ATF through.

Changing Automatic Transmission Fluid (is easy)

Dealer doesn't flush, nor does the local independent Subaru mechanic. They just drain and fill. Dealer claimed it is harmful due to oxidization. I have know idea how to translate that dealerspeak. I can't imagine they would use anything but ATF in a flush, which should be creating oxides (unless they are good alloy oxides) that weaken the components.

[WiscoOB]

It wouldn't hurt to do another one, but I'm sure you'd be fine waiting another 15k. Right now is probably the best time of the year for an ATF fluid change, as the fluid is broken down by higher temps (ie summer driving).

[fun2drive]

I bought a Topsider manual vaccum system to drain ATF from my Super Duty and refill. If you don't mind crawling under the vehicle it is better to see what is on the plug but in 189,000 miles this has worked well. I think changing it is the key and I did just that about every 30K miles. Fluid and my time is a lot cheaper than a new transmission.

Did you buy the AFT from Subaru or other suppliers? I plan to do the diffs and the AFT at the same time.

At least Subaru provides a dip stick for the ATF and front diff.

When I do this with my BMWs there is no dip stick and you have to have the ATF at a particular temp level to get an accurate reading. A total PITA compared to the Outback.

Nice work by the way.

[AltaBrig]

Thanks. ^ I got the idemitsu ATF HP from a seller on ebay. (He sent the stuff from CA locally) Got them for $6.50 a quart. NO tax and free shipping. I bet you can get the same deal. I bought a case of 12 and it arrived in two days. Got the crush washer from a Subie dealer.


The local dealer was charging almost $9 a quart for the Subaru branded HP. Your dealership might be cheaper for the HP.

I almost want to put a quick valve on the ATF to quickly cycle the chocolate colored crap through, but I am not that lazy I will do it every oil change until it is a better color and then go on a 15K schedule. I agree a bit of ATF and easy drains and fills is better than a new Tranny.

I changed the stuff on my 92' F-150 3 times and it always came out a pretty clean red color. I had to replace the filter and gasket each time on that one so it was a bit of a PITA.

Not sure what the Topsider, but it might be less wasteful than repeated drain and fills if it could drain out all the fluid in the OB. Years ago a guy I worked with told me that his Super Duty Tranny (probably a 90') had to be pumped/power flushed and moved through the gears (or something like opening and draining the torque converter with a special tool?-I don't recall) to adequately drain the Tranny. That sounded like a non DIY PITA.

[Scorched]

Alta, great DIY write up.

I did my tranny flush the old fashioned way (I.e. the DIY way) same as you with two important differences.

One, I chose to drop the pan. This makes the job much more of a PITA, so I can't say it is a must do. Subaru dealership couldn't tell me squat about the filter in my tranny (got 3 different answers and 2 different part types) so I wanted to know first hand what it was that was in there. Plus being the first flush I wanted to clean all the sediment in the pan base and the pan magnet out. Subaru in their infinite wisdom uses a liquid gasket for the pan seal which is what made this difficult as you have to scrub the old gasket off and apply a new one before putting the pan back on. The new gasket requires at least an hour of cure time so it tacks up prior to putting any tranny fluid back in, I waited about 3 just to be on the safe side. I got about 5 quarts total out of the system when you include the drained housing.

For those who are ever interested, the 5 speed AT DOES have a tranny filter, it is a pancake type with 2 mounting points that sits below the solenoid shift and sensor cluster.

2nd thing, and probably the one that will help you out the most here alta, the tranny does not drain fully with just a drain and fill. You have another 4-5 quarts still stuck in the torque converter And misc hydraulic passages. In order to get that excess fluid out you have to either a)flush through a machine, or b) let the tranny flush itself through the pump. If you follow the tranny lines from the main case to the radiator, you can disconnect the return stream side after the radiator and do a full flush through the entire system, with pretty minimal "mixing" of the old and new fluids. It's as simple as connecting a line to the discharge, running it into your measuring container and keying over the engine to start the tranny pump. It's better if you have a helper for the first turnover in case you grabbed the wrong line and get a spray from where your not expecting lol.

In my case it took all 12 quarts running through before the fluid coming out was about the same as the fluid going in through the dipstick. I will warn that you have to be careful about the math, I.e. refilling what your draining each time and leaving a little extra. I wound up being a little off with mine and had to make a late run to the dealer for the 13th quart because once the air settled out after running the engine for a bit and shifting through gears, I was a tad bit above the min mark. I preferred to run a little closer to the max mark (without going over of course).

[plain OM]

Originally Posted by Scorched

. . . For those who are ever interested, the 5 speed AT DOES have a tranny filter, it is a pancake type with 2 mounting points that sits below the solenoid shift and sensor cluster. . . . . .

All the Subaru ATs (and many other brands) have a screen on the oil pickup in the pan. It's not a fine filter in the traditional sense, but it will prevent relatively large particles from being pulled up into the lubrication system by the pump.

Incidentally, both the drain-and-fill and the ATF cooler tube methods are discussed in the DIY ATF change thread at: Changing Automatic Transmission Fluid (is easy), and while that thread starts out with a 4-speed, it's pretty much the same for both the 4 and 5 speed.

[Scorched]

Originally Posted by plain OM

All the Subaru ATs (and many other brands) have a screen on the oil pickup in the pan. It's not a fine filter in the traditional sense, but it will prevent relatively large particles from being pulled up into the lubrication system by the pump.

Incidentally, both the drain-and-fill and the ATF cooler tube methods are discussed in the DIY ATF change thread at: Changing Automatic Transmission Fluid (is easy), and while that thread starts out with a 4-speed, it's pretty much the same for both the 4 and 5 speed.

Thanks OM. I hadn't ever seen that page but it essentially reiterates the same method I used.

I exclusively mention the filter because the dealer told me everything from "your transmission doesn't have a filter, to its a standard pancake filter, to its a pancake filter that you should never have to service." While the last statement is probably the most accurate given that its not a true particulate filter, but more of a "rock-catcher" I still think that once the car gets higher in the mileage (maybe 100k or so) ill drop the pan again to check that screen again and possibly replace it depending on what I find.

Just giving others here a heads up in case they get the run around from a dealer like I did.