4EAT Teardown- Nasty Mess of 20 Year Old Trans Fluid!

Subaru 4EAT Teardown!
This video demonstrates the teardown / disassembly of the 4EAT transmission found in 1997 to 2012 Forester, WRX, Impreza, Legacy and other Subaru vehicles.
This particular video is of a 2004 Subaru Forester automatic that was sent to us from Florida.
The transmission fluid is pretty gross- 20 years without a flush or service!
Stay tuned for an upcoming video where we put this gearbox back together.
The 4EAT is at our shop for a complete performance build, including our extra clutch set up, our upgraded performance modified valve body and of course, it's going to also get a high stall torque converter.
The high stall torque converter makes a night and day difference in the performance and acceleration of these vehicles, it almost makes it feel as if you put a second engine under the hood and causes no undesirable effects as far as streetability is concerned.
IPT Performance Transmissions specializes in Subaru high performance automatics and Subaru built autos, as well as performance rebuild kits, modified valve body and high stall torque converters. IPT is recognized as the leader in 4EAT transmission technology and has been upgrading the performance of the 4EAT since opening in 2001.
If you own or work on an automatic transmission equipped Subaru or have one that's got transmission problems, be sure to watch this video to learn about the 4EAT auto gearbox and how to avoid some of the common problems. If you're experiencing any transmission problems or need an upgrade to handle additional torque and horsepower, be sure to contact our experts at IPT Performance Transmissions for a free consultation!
More details on our products can be found here:
www.importperformancetrans.com/
Subaru High Performance Automatic Transmission Parts:
www.importperformancetrans.co...
Tool: Subaru Pinion Nut Tool 499987003
@Reversaru
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The 4EAT Transmission, initially introduced in 1987 Subaru models, is a 4-speed computer-controlled transmission.
This transmission incorporates a lock-up torque converter, engaging in all forward gears except 1st, and it's available in both FWD and Full Time AWD setups.
Since its inception, the 4EAT transmission has undergone continuous development and refinement, with various Subaru models witnessing changes, including a significant redesign in 1997.
This redesign eliminated the 2-4 band, revamped internal components, and introduced a new electronic control system. The second design is easily recognisable by the lack of a band adjusting screw and the addition of a spin on oil filter, which was eliminted in 2008.
For a comprehensive understanding of specific 4EAT operational traits and features, consult the relevant Subaru service manual for the specific year and model you are working on.
Some 4EAT's are also equipped with the VTD (Variable Torque Distribution) AWD system. This AWD system adjusts power to wheels depending on driving conditions. Typical biasing is 45% to the front wheels and 55% to the rear wheels.
Gear ratios are as follows:
Automatic transmission gear ratios:
1st - 2.785
2nd - 1.545
3rd - 1.000
4th - 0.694
reverse - 2.272
final drive ratios (application dependent) - 3.73, 4.11. 4.33

[@iptperformancetrans]

IPT Performance Transmissions specializes in Subaru high performance automatics and Subaru built autos, as well a performance rebuild kits, modified valve body and high stall torque converters. www.importperformancetrans.com/ Find us on Social Media Instagram - @IPTperformancetransmission Facebook - Import Performance Transmissions Tik Tok - IPT_Transmission

[@ronarndt6722]

Thank you for this video I really appreciate it! We do like all the extra work to see the details and the struggles as we can always fast forward 😊

[@emiliog.4432]

Wow. Very impressive work. 👍

[@toddmackey4374]

I have a 4eat 2wd from a 92 legacy that I just disassembled on my bench. I was having some trouble blowing out the low and reverse piston so I watched your video again. I note in particular what you said about the seals causing problems with delay. This transmission looks good inside, with little wear evident. Except all the seals seemed to have hardened and taken a set with age. I have noted a few differences between my '92 and the '04 you have on the bench. Thanks for a great video though.

[@82_KID]

I have a 4EAT.. 2002 Outback. And I do drain and fills regularly and even change the external filter because I generally show my car no mercy.. I am watching this!!!!!!!!

[@link18953]

I recall when I discovered the early 4eat’s front diff clutch pack solenoid failed into full lock, where as later failed into fully open. Bet that was a messy revision discussion for the engineers. Love you work dude.

[@davidb5952]

Great video! thanks

[@vonwesty3544]

Great video! Looking forward to the future reassembly video.

[@iptperformancetrans]

I’m working on it, unfortunately I do it all myself and I’m a way better transmission guy than a content creator or editor ⚙️ I’m trying to make each video a little better than the last and I appreciate every view and every comment.

[@pedlpower]

Me too! This is good stuff! 2010 Forester X, daily driver and beater.

[@mikev350z]

Cant wait to see the 5eat next!!

[@iptperformancetrans]

I have a 5EAT teardown video on my channel and I also have the footage to put together the 5EAT rebuild video in the near future. 5EAT - kzbin.info/www/bejne/Zn-sXqd7f6aGobc

[@mikev350z]

@@iptperformancetrans i watches it to many times this week. I am waiting to see it going back togther!!

[@iptperformancetrans]

@@mikev350z I’m not so great with editing so it takes a while but I should be able to have it done in the next couple of weeks

[@ronarndt6722]

Thanks!

[@caseymoore303]

excellent video. I was trying to understand how subaru AWD worked, specifically ones without a real center diff or viscous coupling. when you pulled the tailshaft off I finally got it. The clutch pack engagement varies, but is never 0. and the split isn't 50/50 due to gearing differences. and the front is driven by that gear engagement in front of the clutch pack.

[@josebermeo9042]

Wow that was amazing, so many pieces in there. How much does a basic rebuild for a transmission like this usually go for? I have an 02 Forester with what seems to be a bad front differential. 😢

[@shezz540]

Good job love it. I have a Subaru Impreza 2008. when I filling differential oil is mixing up to transmission oil which seal I have to change or change the transmission .

[@bluegizmo1983]

I just exploded the front diff (I think, haven't pulled the trans yet) in my '04 Forester XT with the 4eat transmission. The car isn't even that heavily modified, just basically a down pipe and catback and a VF39 turbo running 18psi that tapers down to around 13psi at redline. I was boost braking to do a test launch under a little bit of boost, and the boost had only reached about 5 psi when there was a loud bang and then gear oil all over the road. The transmission bellhousing is cracked all the way around almost 360 degrees right where it bolts to the main case of the transmission. I don't know if there was already a crack in the diff gears or something, or what, because from what I've read these 4eat's and the front diffs are pretty strong. Now I'm having a hard time finding a replacement transmission because I guess the 4eat in the '04 FXT was a one year only transmission and not interchangeable with any other year's and not interchangeable with the non-turbo forester either.

[@llzlk]

Great video explanation! I'm having issues with my legacy 95' and wanted to get into the process! It works fine but after some time, it fails to enter 3rd shift, like the shift won't get in. It happened just a few times, but maybe with your experience could quickly identify any potential problem and where in the transmition is. Just uf you can think of something, I love my subie! Thank you!!

[@iptperformancetrans]

Thank you. It sounds like you may be losing clutch packs.

[@emiliog.4432]

Any TR580s in the future?

[@user-hf6bz2wr4u]

Thanx for Vidoe especially this One . Ddnt slp trying to google what might be the problem got a Subaru Forester XT Singapore Version its making a whirling noise when yu put into drive and it takes some time like its loading and making some shoshing sound in first gear but shifts like new on some gears with no issues. Sometimes it cuts off once it engages into drive or reverse. What might be the problem um down here in Africa with very few spares .when I scan it its showing incorrect gear ratio 1 up to 4. Kindly asking for your help.

[@jonathondaly1460]

is the auto pinion the same as a manual one?

[@douglasharris1427]

Will you be doing any early 4eat transmissions? I have one here from a 1991 Legacy Turbo - would love to see a tear down and rebuild on the "Phase 1" style.

[@iptperformancetrans]

Unfortunately, I don’t see many of those anymore so probably not. If I do get one I will try to do a video but don’t get your hopes up

[@douglasharris1427]

Understandably so! I thought that at one point in time people preferred the early ones for strength - is there any truth to that? Are they still eligible for builds like you're doing to this one? And any chance you have any videos of an IPT 4eat in action?

[@JayGeeJay]

Great video! Can these be built-up to pull a small trailer?

[@iptperformancetrans]

I don’t know what a small trailer constitutes, but yes. they can be made to be more suitable for towing

[@JayGeeJay]

@@iptperformancetrans hey small pop up camper trailer. To haul my golf cart. I would say nothing less than 1500 pounds.

[@jonnysperanzini3897]

I left a similar comment on the build video but it's probably more relevant here: If i have a popping when putting my car in reverse, would you have any idea what that could be? I've ruled out engine/trans mounts and driveshaft (replaced). Would it be more likely a transmission issue (maybe that piston you said goes bad)? I'm kind of hoping it's the ball joint I know is bad lol

[@iptperformancetrans]

I replied where you first commented but I’m at a disadvantage of trying to diagnose a noise via KZbin comments lol That said, I certainly recommend checking the simple things like ball joints if you think it’s relevant before you go into the trans⚙️

[@klord-is9ft]

Video on how to set backlash on these 4eat?

[@iptperformancetrans]

Maybe one day but for now, it’s done like anything else but nut and bolt the pump portion with the pinion in it to the diff case and do the gear set up like that. The carrier bearing housings are adjusters that are threaded, similar to how one would adjust a 9” Ford rear.

[@CRXSLY]

2010 Subaru forester and center coupler starting to make noise when i do slow turn...i do the FWD fuse test and the noise is gone so do you think changing oil and filter will help or is a waisting time and money?

[@iptperformancetrans]

Changing fluid is maintenance and not a repair I have no idea why people think that changing fluid is going to fix anything Would changing engine oil fix a broken engine?

[@CRXSLY]

@@iptperformancetrans thx for your response loud and clear! :)...now time to find a new transmisson :)

[@jonathondaly1460]

my wrx 4eat seems to hang on too long in first sometimes and. bang into second, all other shifts are perfect, it. has a code for vehicle speed sensor, could this cause the. issue?

[@jonnysperanzini3897]

I'm not necessarily an expert on transmissions or anything, but probably. As far as I'm aware the speed sensors collect data for the tcu to know when to tell the transmission to shift, and with at least one known to be bad (the light), I would say replace the sensor and see if it fixes it. If it doesn't, its probably a clutch pack or valve body issue, I'd think.

[@sergios874]

I have my 2009 Subaru forester XT that just made a thud noise and I no longer have reverse. The car drives forward and had a issue with the viscous coupler. Checked fluid and has small metal flakes, do you think it’s better to buy a rebuild kit and fluid and try to fix it or should I try and find a used one?

[@iptperformancetrans]

It’s for me hard to say what you should do but it sounds like your trans is toast. Why not take it out and take it apart and then decide what to do?

[@sergios874]

@@iptperformancetransyeah seems like the next reasonable step I’ll do just that. Thanks for the reply!

[@rodrigoeyer]

Hello, I'm in Brazil and I really needed your help, I saw that you know this exchange rate very well and you have a serious problem with mine. The ATF fluid has entered the differential and mixed with thick differential oil. The gearbox has been dismantled a few times but it's never resolved, it's not about that seal in the tube between the differential and the gearbox, where else could this fluid be passing through, we're lost, I really need your help. Thank very much

[@iptperformancetrans]

There’s several places from which the can leak. If you want to email me I’ll try to go over everything with you [e-mail]

[@rodrigoeyer]

​@@iptperformancetransHello, I sent you the email that day. thanks

[@patonbike]

Former Hawthorner (hawthornite?) here! Just for my curiosity how much power can built 4eat or 5eat handle at the wheels or at the engine. I've always thought that a built 5eat could be faster than 6mt.

[@iptperformancetrans]

Small world.. 4EAT's are usually good for up to 500hp and we have done 5EAT's up to about 600hp