Skip to content
View in the app

A better way to browse. Learn more.

Ultimate Subaru Message Board

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

Legacy/Impreza 4eat AWD swap

Featured Replies

Spent about 3 hours around the boards yesterday trying to get some info. Working on a friend's car. 1990 Legacy EJ22 wagon. It has a blown 4eat, 4.11 ratio. He picked up a 4eat from an Impreza EJ20, details unknown, from a used engine/tranny place, and was told it will be fine. I got the old transmission out. Before I ruin myself getting the replacement one in, how would I discern if this is a compatable exchange? No ratio identification on either that I could find, but have numbers of:

 

Legacy TZ102ZA1AA-JS Small sticker on bellhousing and trans-140161

 

Impreza TZ102ZSAAA-C3 Small sticker-673579

 

Only thing I can confirm is the spline count is the same, and the diameters are the same.

 

Any thoughts?

 

Thanks, Jon

My GUESS is that they are different, at least as far as final drive ratio. There may also be a difference in whether it came for an ODB1 or ODB2 car; I believe that you can tell somewhat by seeing if the tranny electrical connectors are the same.

  • Author

Thanks. I haven't check matched the main connectors. The speedo sensor (?) is cable on Legacy, and electric adapter/sender on Impreza. I believe these parts are swappable though. All along I have had a feeling about this swap, knowing that there are different ratios for all sorts of configurations.

 

Any more?

 

Thanks again, Jon

BTW, I just did a quick search for the impreza tranny's number on both NASIOC and LegacyBBS and did not get a hit on either search.

there are multiple possibilites on the 4EAT so you are right in checking first.

 

can you call Subaru and ask them to look up that part number for you?

 

if it's a different ratio you can still use the transmission, just swap in a matching rear diff.

  • Author

Thanks guys for your efforts! Don't have the car the engine came out of. It is one of those used engine places. Subaru is really nice to put a HUGE label on the rear diff. Too bad they don't put even a small one on the front, or any indication. Maybe it is an import tranny that fell off the boat. :) I am still trying to track down info 'cause I really don't want to put this in and have to take it out.

 

Jon

and have to take it out.
you won't have to take it out, you'll have to swap the rear diff (which is very easy to do and they are very cheap as well).

 

even if you find out the ratio is different, you'd be better off getting the right diff and using this transmission anyway.

  • Author

Yeah, only problem is, I don't know what this tranny ratio is so I don't know which rear I would use. Don't know all the configs of this stuff. Turbo ratio same as non? Impreza ratios different from Legacy? Year differances? Red cars vrs. Blue? I'm too old, my brain hurts. Can I slap a Ford 9" in there? They fit in anything. :)

 

Jon

search car-part.com for impreza trans and hopefully you'll find one with the model number you have. then search for differentials for that model. a lot of work i know, but it could work.

 

some one near charlottesville, va was selling an impreza trans, maybe he has the diff too. check the for sale section.

 

good luck, john. look here: http://www.ultimatesubaru.org/forum/showthread.php?t=62363&highlight=tran%2A

 

Yeah, only problem is, I don't know what this tranny ratio is so I don't know which rear I would use. Don't know all the configs of this stuff. Turbo ratio same as non? Impreza ratios different from Legacy? Year differances? Red cars vrs. Blue? I'm too old, my brain hurts. Can I slap a Ford 9" in there? They fit in anything. :)

 

Jon

Yeah, only problem is, I don't know what this tranny ratio is so I don't know which rear I would use. Don't know all the configs of this stuff. Turbo ratio same as non? Impreza ratios different from Legacy? Year differances? Red cars vrs. Blue? I'm too old, my brain hurts. Can I slap a Ford 9" in there? They fit in anything. :)

 

Jon

If it came out of an Impreza EJ20, then it is positively a WRX 4EAT, unless it is JDM. The final drive is 4.11 for those, at least for the 2002-05 model years. They changed to 3.9 in 2006.

 

If it is JDM, all bets are off...:-\

apparently that transmission was used in a 93 legacy, 2.0L in japan and russia??

 

looks like it might be jdm.

 

http://yosino.ru/motors.htm

http://groups.yahoo.co.jp/group/TAS-net/messages/148?expand=1

http://www.google.com/search?q=tz102zsaaa+&hl=en&lr=&as_qdr=all&filter=0

 

search car-part.com for impreza trans and hopefully you'll find one with the model number you have. then search for differentials for that model. a lot of work i know, but it could work.

 

some one near charlottesville, va was selling an impreza trans, maybe he has the diff too. check the for sale section.

 

good luck, john. look here: http://www.ultimatesubaru.org/forum/showthread.php?t=62363&highlight=tran%2A

  • Author

How did you find that stuff? :) Thanks to my browser's translate stuff I was able to poke around a bit. The Russian page is a listing of Japanese used stuff for sale. As you said, that number shows for a '93 Legacy 16 valve. Australian one shows for '95 Legacy. Still found notheg about ratios. I am still on the hunt though. It has to be "out there somewhere".

 

Jon

can you call Subaru and ask them to look up that part number for you?
have you tried this?
  • Author
have you tried this?

 

It's on my list to do after this: (picture)

post-3814-136027617069_thumb.jpg

  • 1 year later...
It's on my list to do after this:

 

pappy, are you still out there?

i was wondering what happen with your trans swap?

Please sign in to comment

You will be able to leave a comment after signing in

Sign In Now

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.