Jump to content


Welcome to Ultimate Subaru Message Board, my lurker friend!

Welcome to Ultimate Subaru Message Board, an unparalleled Subaru community full of the greatest Subaru gurus and modders on the planet! We offer technical information and discussion about all things Subaru, the best and most popular all wheel drive vehicles ever created.

We offer all this information for free to everyone, even lurkers like you! All we ask in return is that you sign up and give back some of what you get out - without our awesome registered users none of this would be possible! Plus, you get way more great stuff as a member! Lurk to lose, participate to WIN*!
  • Say hello and join the conversation
  • Subscribe to topics and forums to get automatic updates
  • Get your own profile and make new friends
  • Classifieds with all sorts of Subaru goodies
  • Photo hosting in our gallery
  • Meet other cool people with cool cars
Seriously, what are you waiting for? Make your life more fulfilling and join today! You and your Subaru won't regret it, we guarantee** it.

* The joy of participation and being generally awesome constitutes winning
** Not an actual guarantee, but seriously, you probably won't regret it!

Serving the Subaru Community since May 18th, 1998!

Guest Message by DevFuse
 

Photo
- - - - -

Phase II 4EAT swap to Phase I


  • Please log in to reply
12 replies to this topic

#1 monkeyposeur

monkeyposeur

    New User

  • Members
  • PipPip
  • 22 posts
  • Salt Lake City

Posted 22 October 2017 - 11:20 PM

The 4EAT in my 93 Turbo Legacy has 180k. It shifts great and works as it should but I am looking for options in case it shits the bed.

 

I could swap in an NA Phase I Legacy 4EAT, but I want to know what else I could swap in. I am trying to find a JDM TCU so I can run a 20G VTD trans but can't locate a TCU (any help locating one would be awesome!!!).

 

Does anyone have any info how to swap in a phase II 4EAT? I would imagine it would require swapping over the Phase II trans wiring at the very least. I

 

Someone has to have done this, lol.



#2 987687

987687

    Rally Suby!

  • Members
  • 4,214 posts
  • Northern Maine

Posted 23 October 2017 - 06:51 AM

I dunno about the swap, I know it's been messed with those, I've seen threads about it.

 

If you do try and put a phase 2 trans in there, avoid 99-02 as they have issues with delayed engagement with eventual failure. It can be fixed if you wanna drop the valve body and replace seals.

 

Your current trans is actually a pretty reliable box, change the fluid and filter and it should last a long time.



#3 monkeyposeur

monkeyposeur

    New User

  • Members
  • PipPip
  • 22 posts
  • Salt Lake City

Posted 23 October 2017 - 09:31 PM

Yeah, it's a good tranny. I just like to plan ahead since I want to keep the SS forever. 

 

A few strange issues have occurred with it though. There is a rattling type noise coming from the front of the bellhousing, where the torque converter is located. It goes away at higher rpms though. It's not a loose heat shield either. It isn't causing a problem but I don't like it and have no idea what it is. The other problem is the Duty-C solenoid code was flashing. I dropped the tailhousing and replaced the duty-c with a superseded part from Subaru. The torque bind and flashing went away for about two hours and came back. That pissed me off a little since replacing the duty-c is kind of a big job. I did all the FSM diagnostic procedures which indicated a faulty TCU. I replaced the TCU with another turbo TCU of the same year from a working vehicle and got the same flashing and torque bind. I checked the resistors and transistors of the TCU and they were all within spec. So on a whim I swapped in an NA TCU and the flashing is gone as well as the torque bind. It has a slightly different shift pattern now, but I have the POWER mode wired up and with that it shifts pretty good, and at WOT I can run it up to the redline.

 

I have done multiple drain and fills and the fluid is nice and clean. To replace the filter I would have to drop the transmission pan, and the generally don't clog up so I'm not going to mess with that. There isn't an exernal trans filter on my 4EAT like some later models.

 

I am also trying to source a JDM VTD TCU for an EJ20G Auto trans since I can find low mileage JDM transmissions pretty easily, but the TCU is proving impossible to find.

 

I am also installing a RobTune TCU soon so there will be a bump in hp and like I said, just in case it breaks down the line I want to know what options are available. I would rather just swap in a JDM 5MT but my wife drives the car and loves having an automatic even though she can drive a stick just fine.



#4 987687

987687

    Rally Suby!

  • Members
  • 4,214 posts
  • Northern Maine

Posted 23 October 2017 - 09:35 PM

I would highly advise changing the filter, it doesn't take a lot to reduce oil flow through the filter causing other problems. Dropping the pan really isn't a big deal.



#5 monkeyposeur

monkeyposeur

    New User

  • Members
  • PipPip
  • 22 posts
  • Salt Lake City

Posted 23 October 2017 - 10:52 PM

OK, If I get some extra time I'll think about dropping the pan. I know it won't be a big deal although some report issues getting the pan to seal. I just replaced the steering rack, tie rod ends, oil pan, power steering lines, duty-c solenoid, did three drain and fills so I'm a bit tired of being underneath the car for a while at least.

 

Most of what I have read on bbslegacycentral says not to bother with replacing the internal filter but I'll definitely keep it in mind.



#6 86BRATMAN

86BRATMAN

    Elite Master of the Subaru

  • Members
  • 3,926 posts
  • Tazewell Virginia

Posted 24 October 2017 - 07:42 AM

Sealing problems are directly related to people bending the pan lip when removing it, and not getting all the old rtv off both pan and transmission.

The problem with the phase 2 tcu swap is that it will be expecting to see signals that phase 1 ecus do not send. I've tried running a 97 and 98 25d ecu in a 99 GT for testing purposes. Both put the tcu into limp mode despite all 3 being "phase 1 ecus".

#7 idosubaru

idosubaru

    Elite Master of the Subaru

  • Members
  • 23,415 posts
  • East Coast

Posted 24 October 2017 - 01:46 PM

Internal filters are pointless to replace. It’s just a screen and other than a couple flecks they’re never clogged. If it’s clogged your trans ain’t long for the world anyway and would probably fail with any increase or improvement in fluid flow LOL.

#8 idosubaru

idosubaru

    Elite Master of the Subaru

  • Members
  • 23,415 posts
  • East Coast

Posted 24 October 2017 - 01:49 PM

Sealing problems are directly related to people bending the pan lip when removing it, and not getting all the old rtv off both pan and transmission.

The problem with the phase 2 tcu swap is that it will be expecting to see signals that phase 1 ecus do not send. I've tried running a 97 and 98 25d ecu in a 99 GT for testing purposes. Both put the tcu into limp mode despite all 3 being "phase 1 ecus".

interesting, nice hit. 99 is a phase II trans so the Phase I ECUs somehow accommodate that?

#9 monkeyposeur

monkeyposeur

    New User

  • Members
  • PipPip
  • 22 posts
  • Salt Lake City

Posted 24 October 2017 - 09:00 PM

Sealing problems are directly related to people bending the pan lip when removing it, and not getting all the old rtv off both pan and transmission.

The problem with the phase 2 tcu swap is that it will be expecting to see signals that phase 1 ecus do not send. I've tried running a 97 and 98 25d ecu in a 99 GT for testing purposes. Both put the tcu into limp mode despite all 3 being "phase 1 ecus".

 

I'm confident that if I pulled the pan I could do it right. I've build a few shortblocks and swapped engines and trannies, etc.

 

Thanks for the info. I was wondering the the ecu had to communicate with the tcu or if they were independent. So it seems like the only way to get a phase 2 to work properly would be to do a complete wiring harness merge and engine/tranny swap. I was looking into doing that but I have since decided to go with a RobTune ecu. 



#10 86BRATMAN

86BRATMAN

    Elite Master of the Subaru

  • Members
  • 3,926 posts
  • Tazewell Virginia

Posted 25 October 2017 - 06:16 AM

If you're on Facebook you may be able to get some help finding the vtd tcu you're looking for from some of the Australian and New Zealand members on the subaru pages. Ben Thurgar has been a good source of parts for many people in the last few years.

#11 monkeyposeur

monkeyposeur

    New User

  • Members
  • PipPip
  • 22 posts
  • Salt Lake City

Posted 25 October 2017 - 09:50 PM

Cool! I'm not on FB but I'll try and get in touch with that Ben dude! My buddy said he found a guy in Australia that would find me one. Wonder if it's the same guy. Weren't you looking for some 22T pistons a while back on bbs? I have a set that I might toss soon.



#12 86BRATMAN

86BRATMAN

    Elite Master of the Subaru

  • Members
  • 3,926 posts
  • Tazewell Virginia

Posted 26 October 2017 - 11:32 AM

I was looking for some a while back, I ended up getting two sets and never using them lol. Ben is in NZ, but there are several helpful guys from AUS. Hopefully they'll be able to find the tcu you need.

#13 wtdash

wtdash

    Subaru Nut

  • Members
  • 1,521 posts
  • N. ID

Posted 15 November 2017 - 04:54 PM

 I have a set that I might toss soon.

 

If you plan on keeping your SS w/the EJ22T 'as is' I'd keep those as I've blown @ least one ringland....but maybe it'll be time to upgrade to forged?






0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users