4EAT to 02' WRX 5MT swap - Success!!

[skid542]

First off, my apologizes as I know there is a recent thread detailing the 02' WRX tranny swap but for the life of me I cannot find it. If anyone can direct me to this thread, I would be very appreciative.


As a brief forward, I'm going to be swapping my current 4eat to an 02' WRX 5mt that has had the LGT 1-2 gear/mainshaft swapped in. Some of you may recognize this tranny . This swap will occur in the next month or so. The questions I currently have pertain the mechanical aspects of this project.

Tranny crossmember - I am receiving the updated 'H' style tranny crossmember. According to Dscooby this may require slight shimming. I will search on RS25 for this as suggested but wouldn't mind a few starters. I will be buying a new Grp N tranny mount to compliment the new Grp N motor mounts I will be installing.

Rear Diff fitment - I am receiving the proper lsd rear diff to match the 1.1:1 center diff and the corresponding axels. I am also getting a corresponding driveshaft so I should be good on those two fronts. However, are there any changes in how the diff actually mounts to the car?

Starter Hole/Stub - As I currently understand it, the 02' WRX tranny has a hole or stub that needs to be adjusted or is different than the mounts on the EJ22T bell housing. This is an area where I need to do a little more searching and the above mentioned thread likely addresses. I am assuming this is an issue that is pretty apparent/easily fixed?

Clutch choice - This is a big one and probably one of the deadest horses that gets beat on. Since I'm doing a full swap I don't care about differences in WRX vs. SS flywheels. My current plan is to get a new 12-14 lb lightweight WRX flywheel (I will be doing a lot of Auto-X with this car). The real question on the clutch is whether to get a stocker or a Stage 1 clutch. My foremost concern is not breaking my nice new tranny. I'm looking to take the engine power output to the limits of the stock longblock and/or the tranny - my current understanding puts this at around 300 chp. My current thought is to go with a standard Exedy stock replacement and stay away from the pucked clutches. I would prefere to have slip in the clutch and not shatter gears. Having the wider LGT 1-2 should help a little but I'd really prefere to keep the teeth intact. Folklore on Nabisco says the stock clutch and P/P should hold around 290 ft/lb. I guess I don't have a specific question on this one but am instead fishing for opinions/input.

I think that's all I have right now but I'm sure I'll be back here and there through this swap. Any and all comments or input is welcomed as I know a lot of the guys here have walked this road already and a bit more experienced than I am.

Thank you in advance.

[skid542]

No takers, not even a 'search noob' ?

[n2x4]

Tranny crossmember - I am receiving the updated 'H' style tranny crossmember. According to Dscooby this may require slight shimming. I will search on RS25 for this as suggested but wouldn't mind a few starters. I will be buying a new Grp N tranny mount to compliment the new Grp N motor mounts I will be installing.

I'm not aware of issues with swapping the crossmember. In my experience, it fit fine. I'd be curious to know why someone would need to shim it.

Rear Diff fitment - I am receiving the proper lsd rear diff to match the 1.1:1 center diff and the corresponding axels. I am also getting a corresponding driveshaft so I should be good on those two fronts. However, are there any changes in how the diff actually mounts to the car?

Only thing you need to watch for is the length of the studs in the back cover of the diff. The wrx ones may be to long. If so, you'll need to swap in the studs from your legacy diff.
Oh, and the 1:1.1 ratio is not actually in the center diff. It's actually in the transfer gears. The diff slides onto a shaft connected to the gears. Not a big deal, but the center diff is the same one in every phase 2 subaru transmission here in the US.

Starter Hole/Stub - As I currently understand it, the 02' WRX tranny has a hole or stub that needs to be adjusted or is different than the mounts on the EJ22T bell housing. This is an area where I need to do a little more searching and the above mentioned thread likely addresses. I am assuming this is an issue that is pretty apparent/easily fixed?

You're correct. Phase 1 transmissions had a stud in the transmission on the hole for the lower starter bolt. Phase 2 transmissions (such as the wrx) did not have these. You just need to tap the lower hole, and add a stud. I just use a nice size bolt, screw it in a little past what I've tapped to "seat" it well, and cut the head of the bolt off. If you go too big with your new stud, you'll have to drill out the hole on the starter, so watch your sizes.

Clutch choice - This is a big one and probably one of the deadest horses that gets beat on. Since I'm doing a full swap I don't care about differences in WRX vs. SS flywheels. My current plan is to get a new 12-14 lb lightweight WRX flywheel (I will be doing a lot of Auto-X with this car). The real question on the clutch is whether to get a stocker or a Stage 1 clutch. My foremost concern is not breaking my nice new tranny. I'm looking to take the engine power output to the limits of the stock longblock and/or the tranny - my current understanding puts this at around 300 chp. My current thought is to go with a standard Exedy stock replacement and stay away from the pucked clutches. I would prefere to have slip in the clutch and not shatter gears. Having the wider LGT 1-2 should help a little but I'd really prefere to keep the teeth intact. Folklore on Nabisco says the stock clutch and P/P should hold around 290 ft/lb. I guess I don't have a specific question on this one but am instead fishing for opinions/input.

Your logic sounds exactly like mine. Go with a stock Exedy replacement, you'll be happy and that clutch is supposedly good for right around 300HP.

Things I didn't see you mention:
1. Driveshaft- What car is this coming from? If it's from a old legacy, you'll need to swap pinion flanges on the diff (the end where the driveshaft bolts to the diff). Subaru changed the spacing on the rear diff flange somewhere around 1995.
2. Shift linkage- Phase 2 transmissions have a different shift linkage setup. All they changed was the knuckle, but if you compare the two side by side, they won't really work interchangeably. Just make sure you have a shift linkage out of some Subaru 1999 and up, and you'll be fine.
3. Axles- Make sure you're using WRX sedan axles. Wagon ones are too short.

Sorry I didn't see this thread last nite, I actually had stuff to do on a Friday nite other than post on the internet

Good luck with your swap! If you need answers, just ask and I'd be glad to give you some tips.

[skid542]

Thank you! I appreciate the input.

I am glad to hear you had no troubles with the crossmember. I believe it was Dscoobydoo who stated in this thread - http://bbs.legacycentral.org/viewtopic.php?t=37748 - that there was an issue with the newer crossmembers. Perhaps he will chime in here.

Thank you too for clearing up my terminology on the center transfer gears. I get a little ahead of myself sometimes but I do appreciate you helping keep this thread clean of mis-information.

After a bit more research and your confirmation I'm going to go with a stock Exedy clutch mated to an ACT Streetlite flywheel. I've seen quite a few Ebay sales that have a kit that includes an F-1 Racing lightweight flywheel for about a $100 less but I'm still unsure about using them. I know I can trust the ACT and I've seen considerably more reviews of it, particularly on the BBS.

With regards to the driveshaft, linkage, and axels... Matt Monson is who I'm buying the tranny from and is who is including the driveshaft, linkage, axles, and crossmember with the transmission. I am assuming that he is aware of these issues as he is aware that I'm doing the 4eat -> 5mt swap and will provide the appropriate parts.

I was aware of the bolt pattern on the driveshaft and the axle lengths but the shift linkage issue was new knowledge.

Again thanks, I'm sure I'll have a few random questions here and there but man I can't wait to get rid of the 4eat .

[n2x4]

Sounds like you're well on your way, and a bit more prepared for the phase 2 trans swap than I was my first time .

While I'm nowhere near 300hp, the clutch has been working for me just fine. For the price, you can't beat it! A clutch is much cheaper than a trans, and from the research I've done, it should fit the bill. Worse case is you burn through it and it's a learning experience.

As far as the crossmember goes, I'm not familiar with the issue. I do know that the front subframe crossmember from a WRX requires shimming, but that's all I know.

While I don't know him other than what I've read in his posting, Matt definitely knows his stuff, and only speaks from experience. I've learned there's a lot of "internet mechanics" that post without knowing what they talk about, but you're in good hands.

[dscoobydoo]

My apologies, in that I thought you were talking about the ENGINE not the transmission crossmember. Everything that was posted before this is right on.

But I will re-post the important things to watch for:

The driveshaft lengths from auto to manual differ and may also slightly differ by car. So make sure you have the right length.

The shift linkage will have to be from a later model car- 98- to even 07 should work.

Someone else covered the starter bolt/hole issue. Take care of that before you get going deep into the swap.

Lastly, I would actually opt for a stage 1 clutch. They are not "puck" style clutches, and the only difference between stock and stage 1 is that the material is a bit better for holding power. Since you plan on pushing the engine a bit, I think you will like the stage 1 better.

[AWD_addict]

As for your shift linkage, you may want to consider getting the STi short shifter that is meant for that transmission. That way you have all new bushings and nothing is corroded and shitty. I got the one for a '98 LGT when I swapped that transmission in, it shifts crisply.

It's not cheap, but it looks like you are spending a pile on the swap anyway.

[skid542]

Dscooby (Drew? I'm sorry ) - Thanks for the clarification on the tranny support. I don't mind some fabrication as need be but I do prefere 'plug and play' mechanics. The driveshaft that I'm getting is a 5mt shaft though I will be keeping my 4eat for when/if I eventually upgrade to the 6sp. I still think I'm going to go with the stock clutch. I agree that the stage 1 would definately be better as I do plan to get the motor up to the 300chp mark before too long. But while I've been driving a stick for the last 10 years I know in a race situation a shift will inevitably get missed. As such I'd rather have the clutch slip in that situation than shock the tranny harshly. We'll see, if I have to swap clutches that's a lot easier/cheaper than tranny's. I haven't purchased anything yet, but I'd be lieing if I said I wasn't concerned about all the broken 1-2 gears over on Nabisco.


AWD - I will get a short shifter before it's all said and done. However, right now I'd rather spend the money on an adjustable rear sway bar. And my money pile is only so big .

[biggreen96]

sounds like a fun project!

I used the stock wrx clutch disc and pressure plate up to ~20psi without it slipping.

So I second the stock clutch, it's oem and practical.

[skid542]

I know have cool new parts on order .

Called Rallispec and ordered new Grp N motor mounts, trans mounts, and pitch stop.

Called Gripforce and ordered Exedy stock replacement clutch kit and an ACT Streetlite lightweight flywheel.

[n2x4]

Don't forget some nice new gear oil. I use Redline fluids since I can source them local (Summit Racing FTW).

I have heard good stuff about Motul and Amsoil. I have a case of Amsoil waiting for my next oil change...

[skid542]

As I continue to think all this through in preperation for game day I'm coming up a with few more questions. I'm going to start asking all those questions here in an effort to have an inclusive thread and not scatter information through the forum. Once I receive an answer on the pressure plate to flywheel bolts thread I'll move that info here.


So that said, my next question is another 'noob' question.

Not having dropped a rear end before, is it possible for me to drop the existing diff and put in the new diff with corresponding axles without upsetting my alignment? Because I've slotted the rear struts and used camber bolts it's a little bit of a PIA to get aligned (and consequently a little expensive). If I have to, then I will but I'd prefere to keep the current settings. So how do I swap the rear leaving the hub/strut attachment alone?

I know for the front I'm just going to pop out the ball joint to give myself the wiggle room to move axles around but am unclear on the rear.

Thank you again for the help.

[AWD_addict]

You probably won't need to touch the strut bolts when you drop the rear end. As the differential comes out of the car, there's more room to take the axles off.

[skid542]

Awesome. I'm assuming that means there's room to but the new axles in?

Thanks for the input.

[skid542]

Okay. I've always tried to hide my electrical ineptness but I guess I'll have to set my humility asside...

I'm getting all the electrical stuff put together and have a few questions.


All pinout diagrams are numbered looking into the connector?

Is the B15 connector located on transmission itself and the mating end in the transmission tunnel?

Do I have to mess with the starter relay interlock? Can I leave it alone and just becareful to clutch in before starting and address it later? The car will crank when pins 11 and 12 are connected together?

To make the reverse lights work I simply connect pin 9 to pin 2 (AT -> MT) and pin 10 to pin 4 (AT -> MT).

For the neutral switch I connect pin 1 to pin 1 (AT -> MT) and pin 4 to pin 3 (AT -> MT). I then snip pin 18 on the B36 connector to kill the neutral light on the dashboard.

The ECU AT/MT identifier pin is pin 20 on the ECU B49 connector. I simply snip this? I ask because I know Josh did this initially on his 90' ECU and then he states that he had to reconnect it for the 92' ECU. I believe all SS ECU's were the same so I'm not sure how this falls into the 90' vs 92' ECU senario. Can someone verify this issue for me?

I know I'm excluding the cruise control for right now. As it sits, I can't get my defrost or cruise control to work since I pulled the dash out last fall so I'm happy worrying about the cruise for a later moment in time. As I understand it, I don't need to mess with tranny connectors to adjust this anyways so there's no need mess with it during the swap itself.

Any help/input/comments would be appreciated.

Thank you.

[Legacy777]

Okay. I've always tried to hide my electrical ineptness but I guess I'll have to set my humility asside...

I'm getting all the electrical stuff put together and have a few questions.


All pinout diagrams are numbered looking into the connector?

Yes, and you need to make sure you are looking at the correct connector. The male & female ends have different names. For example, the corresponding connector for the B15 connector on the transmission is E18. Typically though, the diagrams will only show one as to not confuse things.

Is the B15 connector located on transmission itself and the mating end in the transmission tunnel?

Yes it's on the trans, and it mates near the back of the engine and near the fire wall.

Do I have to mess with the starter relay interlock? Can I leave it alone and just becareful to clutch in before starting and address it later? The car will crank when pins 11 and 12 are connected together?

You technically do not have to mess with the interlock relay. Just jumper pins 11 & 12. I've actually bypassed my starter interlock relay harness because it was giving me starting issues. I either need to redo the wiring or replace the relay.

To make the reverse lights work I simply connect pin 9 to pin 2 (AT -> MT) and pin 10 to pin 4 (AT -> MT).

Yes, reverse lights are pretty easy.

For the neutral switch I connect pin 1 to pin 1 (AT -> MT) and pin 4 to pin 3 (AT -> MT). I then snip pin 18 on the B36 connector to kill the neutral light on the dashboard.

Yes

The ECU AT/MT identifier pin is pin 20 on the ECU B49 connector. I simply snip this? I ask because I know Josh did this initially on his 90' ECU and then he states that he had to reconnect it for the 92' ECU. I believe all SS ECU's were the same so I'm not sure how this falls into the 90' vs 92' ECU senario. Can someone verify this issue for me?

The hitachi ECU's follow the FSM, so if it's a tleg, snip it for MT.

I know I'm excluding the cruise control for right now. As it sits, I can't get my defrost or cruise control to work since I pulled the dash out last fall so I'm happy worrying about the cruise for a later moment in time. As I understand it, I don't need to mess with tranny connectors to adjust this anyways so there's no need mess with it during the swap itself.

Any help/input/comments would be appreciated.

Thank you.

[skid542]

Josh, thank you for the prompt and concise reply. I'm getting a really good feeling about this swap. Your write up on your site has been extremely helpful.

[skid542]

As a follow up to my question in my other thread -

The bolts to clamp the pressure plate to the flywheel have P/N 011308180 and they get torqued down to 12-15ft. lbs. You will need six bolts.

It's a bolt/lock washer combo, and Subaru genuine parts prices them out at $0.56 each.

This information is from n2x4 - thank you very much.

[AWD_addict]

Don't forget new flywheel to crankshaft bolts too!

[skid542]

^^^ Shouldn't the bolts that attach the flex plate to the crank also work for the flywheel?

[n2x4]

They should, but flywheel bolts are longer, and a different P/N.

800210660 are the correct ones.

[skid542]

Fair enough, I'll do it the right way . Thank you.

[Legacy777]

Josh, thank you for the prompt and concise reply. I'm getting a really good feeling about this swap. Your write up on your site has been extremely helpful.

You're welcome.

Let me know if you have any questions during the swap.

[Matt Monson]

As for your shift linkage, you may want to consider getting the STi short shifter that is meant for that transmission. That way you have all new bushings and nothing is corroded and shitty. I got the one for a '98 LGT when I swapped that transmission in, it shifts crisply.

If it was corroded and shitty it would be in the trash and not something I would sell.

[Matt Monson]

^^^ Shouldn't the bolts that attach the flex plate to the crank also work for the flywheel?

The auto tranny ones are too short. I frequently reuse these bolts. If you want a set I'll throw them in with the other parts. If you take a survey, like the head bolts, you'll probably find about a 50-50 split on the argument of whether it's OK to reuse or whether you should buy new. I'll let you do your own research and draw your own conclusion, but there's a set for you if you want them.