Engine Transmission Swap

[davidsonje99]

Hi,

Thanks for the help. I intend to swap a 97 legacy 2.2 for my finicky and aged Phase 1 2.5 in my 99 Legacy GT. I am hoping to increase fuel mileage by going to the venerable 2.2 and do away with the not so reliable, oil leaky, head gasket issues, early 2.5. The Subaru shop manual shows slight gear ratio differences in the 99 2.5 automatic transmission in contrast to the 99 2.2. 4 speed automatic. What do you think? Can I plug and play without running into transmission mating problems or performance problems? I am wondering if both the 2.5 Phase 1 engine block and 2.2 engine block have the same number of xmission bolt holes in the same places for my 2.5. auto?

[n2x4]

Are you sure the 2.5 in your 1999 Legacy is Phase 1? If it's SOHC it's Phase 2. 1999 was the year of the Phase 2 change over, unless you got some mix of unknown parts.

As far as bolting things up, they'll go together the exact same way. Block bolting points are the same. Regarding differences between a 99 2.2 and a 99 2.5 trans, I wouldn't anticipate any problems. The TCU might be slightly confused but I could see it adapting. That was the case when I did the same swap on a 98 (phase 1).

[davidsonje99]

I am sure it is a Phase 1 2.5. DOHC engine. Specifically it is a EJ25D engine. Also I counted the bolt holes on the back of my JDM 2.2. and I find four with two guide pins. The xmission in my Legacy shows 6 (probably with two hidden guide pins). I am with you, I think I can just plug and play even with 4 instead of 6 mating bolts. As for performance, I might lose some acceleration and the engine may labor more than the DOHC EJ25, but I should still get better mileage. As a side note, I scanned ebay for a 2.2. auto; many are available and I noticed that most listed a fitment for both the 99 2.5 and 2.2. engines. If it doesn't pan out, I can always swap transmissions too if needed. Thanks for your response.

[n2x4]

That's kind of strange, the 6 holes were introduced with phase 2, 4 were from phase 1.

They'll still line up, the only difference you'll have to look at and work with is how the starter bolts in. Pretty sure Phase 1 used 1 studs on the starter and phase 2 was 1 stud one bolt.

[wtdash]

Hi,
FWIW, I swapped a '95 EJ22 w/the EGR into a '99 OB.

I have a post on here or the USMB w/specifics.

I just left 2 of the bolts unused...also remember to check where the dowels/pins are installed, so they don't get in the way (yes, I learned this one). IIRC, the starter bolted on fine....i think if you use a phase 2 block w/the phase 1 trans it might not....I have read where just using one mounting bolt for the starter works fine, if you have to.

The '99 was the transition year, and I've yet to read definitively, but I 'think' all blocks were Phase 2 starting in '99, but the Legacy OB/GT EJ25 kept the DOHC heads, for whatever reason (along w/the HG issues!) and are 100% the same or compatible sensor-wise as the earlier OBDII models.

I put the flexplate from the EJ25 on the EJ22 to mate up to the 4EAT, did a little vac line rerouting (2.2 has the charcoal canister in the front; '99 is in the rear somewhere but just reused the EJ25's lines), and it started and ran fine on the EJ25's ECU (yes, the '99's).

BTW, you'll also need the y-pipe/header from the '97 since it's a single-port exhaust; all the EJ25D and '90-96 (?) EJ22's were dual-port.

Edit: My .02 on performance. The '97 had more torque than the earlier 2.2 so shouldn't be bad @ all. If you haul a lot of stuff/people you'll notice it more. You can get Delta cams for the 2.2 that'll put your torque in range of the 2.5. BUT, if your 2.5 hasn't been heated up repeatedly and just needs the new HG job, then I'd fix it, reseal it and reinstall. When they're run hot the bottom-end bearings wear quickly, and then you'll need a new block.

GL,
Td

[Xander_X]

ok at least someone can tell me if I'm wrong in saying a 93 or 94 transmission will work right? lol