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

[AWD_addict]

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

I'm not trying to insinuate that you would. I was just bringing up the option.

[skid542]

Hehe.

Matt, I appreciate the offer to include the bolts for the flywheel/crank but I can get brand new ones for $0.64 from the dealer. As such I'm just going to get new ones for the simple sake of using all new stuff in the clutch assembly. Thank you though.

[Matt Monson]

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

I'm not trying to insinuate that you would. I was just bringing up the option.

I was just saying...

[skid542]

Well I'm into the swap, it's going well. Motor and tranny are out, now to start putting it all back together and do a little wiring.

I do have one quick electrical question though - for the AT/MT identifier pin. Josh's website states Pin 20 on the B49 ECU connector. The FSM manual only shows a B48 connector and no B49. I'm assuming I want to snip the pin on B48 and that B49 was a typo. Just wanted to double check before I cut any wires .

The other quick question, I know the WRX axles are different lengths. Which one goes on which side?

Thanks a ton guys.

[skid542]

Okay, scratch the above question. More research showed that it was indeed a typo on the Surrealmirage website. It is the B48 connector.



My next question is this. Since my tranny does not have a 4 pin connector, instead has two lone 2-pin connectors - does it matter what order there are connected. By this I mean, when I identify which connector is the reverse switch does it matter which pin go the the AT B15 pin 9 or pin 10? As long as they are both connected it should work correct?

The switches on the tranny are just simple N/O or N/C switches?

[Matt Monson]

Lee,
I marked the axles with left and right in tape. I don't know which is which by memory, but they are marked for you.

Also, I got your message. You should be able to feed the speedo cable back into the gauge, but will likely have to pull the gauge out of the dash to do it.

[skid542]

Thanks Matt. I did see the markings, and they were very helpful. I'll do a more complete status update this evening or tomorrow at lunch.

But, the rear end is all put back together and ready to go.

The idiots at the dealership only sold me 6 bolts for the flywheel - I need 8 - I know I should have checked when I got them. I just assumed... and yeah... So I'm stuck until I get more bolts.

Have had a couple of small issues but easily worked around.

I did get the speedo cable back together and I did end up tearing into the dash/instrument panel. Worked out okay I guess as I had to run new wires for the meth/water injection setup.

Tranny is pretty much ready to go in. I got all the parts/brackets swapped over and the tranny mount on. I need to get a dipstick for it and the plug that holds the clutch fork in (couldn't find it so I'm guessing it fell out during shipping?) I also need to get the centering spring. But otherwise it's ready to go into the car.

So, all in all it's going well. I'll post more notes/findings later.

Again, a thanks to everyone who's helped out so far.

[Legacy777]

I thought I fixed that typo. I need to make myself a note and go back and do that.

Thanks

[skid542]

Okay, Matt is taking care of me and getting me the parts I need by the weekend - thanks Matt. Have I mentioned how awesome his company is?

I thought I would provide some notes on last weekend's progress while everything is still fresh. I apologize if it seems a little scattered but I wanted to get the information down and I can clean it up as the project gets completed.


Rear diff replacementl

This was initially a real PIA. I had asked about dropping it without touching my suspension and was told that I could. This is likely true, but I didn't have the car high enough in the air to let the axles come all the way out. As a result, we got it part way out and after pushing/pulling/wiggling for a bit I decide to just cut one of the axles. I apologize to the Subaru gods for cutting a perfectly good axle, but there comes a point where you get frustrated and just do it....

Putting the axles back in was not going well at first. We put the axles in and then tried to work the diff up into place - this just didn't work.

So, what we found, just remove the single long bolt that connects the lateral links to the hub. This will provide ample play in the hub to swing it up and out of the way making installing the axles after the diff has been re-installed to the car. I wish I'd done this from the get go as it's super easy and makes it all go very quickly. I didn't have to touch any of the other bolts on the strut attachment or the trailing arm.

Many of you probably already know this, but I didn't and hopefully someone will learn from my mistakes here .

Matt had kindly marked my axles with a left and a right tag. I took left to mean drivers side and right to mean passengers side. Axles went in without a hitch and sealed great along the diff.

Electrical Wiring

For many, including me, I was a bit worried about all of this as I can be a little dense sometimes on electrical stuff. There's also something inside that says I shouldn't be cutting factory wires around things like the ECU.

That said, this really was pretty easy. I snipped the identifier pin on B48. This wire was black with a white stripe. I then snipped the neutral indicator wire on the blue B38 (? need to check my notes or page 1 of this thread). The pictures Josh has on his website show this plug very well. Both this plug and the ECU were very easy to get to with the lower panel removed.

Next was the tranny wiring. Taking the 12 pin connector that attaches to the tranny, I pulled the wiring loom off to expose all the wires. I then shorted pins 11-12 together, soldered the joint and heat shrinked it. I then tucked all this back up into the wire loom. I then committed the car to be only a 5mt by cutting through the 16 pin connector wire bundle. It just cleans things up in the engine compartment and makes moving wires around a bit easier. I don't believe this will come back to bite me in the rear.

I have an extra connector from an 4eat tranny, thank you Todd, that I then got ready to splice onto my 5mt tranny. I didn't splice things up because I only have two 2-pin connectors to work with opposed to a single 4-pin connector. Until I get the tranny in the car and shift it around, I'm not sure which is the neutral and which is the reverse. But this should be easy.

I did not work on the cruise control. My C/C hasn't worked in over 1.5 year and while I miss it - it hasn't been enough to spend the time to fix it. I actually went ahead and pulled the pump and actuator out of the engine compartment this weekend to continue cleaning it up.

I will note, and this is important, when reading the pin diagrams - they are numbered such that you are looking at the back of the, i.e. the wires going into the slots. I discovered I was reading them wrong after I snipped the neutral indicator wire and then went to snip the ECU identifier pin only to discover there wasn't a wire at pin 20... which is why I never snip wires right up against the connector and leave myself room to splice it back.

Tranny Mount

This started out pretty easy. The AT mount is a single horizontal mount with three bolts on each side going into the chassis. The MT mount is the classic H-brace that has two bolts going into the chassis where the AT mount goes and then the other two go into the chassis up beside the lower control arm mount. I had to scrap away years of icky and sticky goo to get to a clean metal surface. However, Subaru did install these nice little plastic plugs in the bolt holes to keep them clean. Just clean it all up, pull out the plugs and you're good to go.

There is a note here to pay attention to - the forward tranny mount bolts are larger than the rears. This means that unless you have extra misc. metric bolts laying around you won't have what you need to install the tranny mount. I don't know what size they bolts were, but they are a step up in dia. from the rear bolts. Somone may be able to chime in here. I *think* the bolts I used came from the top back seat seatbelt mount.

Unfortunately, I ran into a large problem installing the mount. As I was putting in the driver's side front bolt, the welds holding the nut to the chassis broke. This occured before I was even really torqueing it down. It was starting to get tight and then *pop*, it started spinning. My friend and I are still trying to figure out where we want to cut into the car to weld this nut back. Right now we're thinking about using the small flat area just infront of the mount, it's located at the bottom of the firewall basically.

Other than that hang up, the tranny install went great.

Shift Linkage

The shift linkage I was given is from an 03' WRX. It dropped in with no problems.

There are a couple of notes here. You will need to take out the three posted torqx screws that hold down the airbag computer in order to get the AT shift linkage out. You don't have to disconnect any wires, just take out the three screws that are easily reach and then lift it up out of the way to get the AT shift wires out from under it. The other option is to snip the wires I guess, but I suspect that will interfere with things when you go to install the 5mt linkage. This is super easy, provided you have the right torqx bit.

The 5mt linkage drops right into place up top. Uses the same screws and everything. Underneath there is a place for the linkage bracket (I don't know the proper name) to mount and the threaded holes are already in the chassis. The pictures I'll be putting up later will clarify this. You will need a few bolts to put these in, so again, if you have misc. metrics laying around you're in great shape. Otherwise you'll need them. I'm sorry I don't have the bolt size, but it took a 12mm socket FWIW.

Do make sure you have both tranny connecting/shift rods above the tranny cross member before you bolt things down in the cabin. Otherwise you'll have to do what I did and undo the bolts up top to get the clearance to move things were they need to be down low. This is pretty minor, just a note as something to watch for and save yourself 5 min.



Well that's all the time I have today at lunch. I'll try to get some more up tonight or tomorrow. Once this is all done I'll have a lot of pictures to share as I've been snapping a bunch.

Again, thanks to everyone for the help so far and if there anything in my description above in this post that is incorrect - please let me know.

[AWD_addict]

Cutting a good axle to get the diff out?:smt108

If you need extra bolts don't forget to scavenge parts from your old AT.

[skid542]

I was replacing the axle anyways. And at the time it appeared to be the 'cheaper' solution than a new alignment - running rear camber bolts and slotted struts doesn't help when it comes time to go in for an out of stock spec alignment.... I didn't know that I could get the clearance I needed without upsetting the strut/hub attachment. I'm not proud of the decision, but I stand by it. Plus, how often do you see someone looking for a single spare rear axle .

And as far as extra bolts, you really don't get anything from the AT. At most, you get 8 short bolts that hold the flexplate to the crank, two extra tranny mount bolts, and four bolts that connect the flex plate to the TC. Some of these would probably work to attach the shift linkage to the chassis. But honestly, there's not many extra's that come from the AT side of things that help you out when you have a 5mt.

[Aerotech]

Thanks for the write-up, Lee, details like this are gold.

[AWD_addict]

If you're running different style axles now, that makes more sense.

I grabbed extra bolts from my old AT because I had to take the pan off anyway to dump it, and they come in handy later for other random areas of the car. AT oil pan bolts are the same as engine oil pan bolts, and may be less rusty.

[skid542]

I apologize for the short post and brief notes. I will clean them up in a few days but I wanted to get notes down from this weekend while they were still fresh.

The swap's almost over. Motor and tranny are in the car and the shift linkage is all hooked up. All that is left is install the driveshaft (see notes below), bleed the clutch, re-install the exhaust, and hook up the intake.

This weekend has been a bit of a challenge and has required some patience. I've also learned a few things...

The bolts that attach the front of the tranny cross member to the chassis are 12x1.25. Subaru does make bolts that are between a 10mm and 12mm that will fit into these holes and thread, but will not hold when you torque them down. This gives the impression that the nut inside has broken loose..... Why they make a bolt like this I don't know but if you grab one out of your spare bolts bag and don't realize it, it'll mess with you.... A proper 12x1.25 solves this.

Not all rear drive shafts, not axles but drive shaft, and diff flanges are created equal. The drive shaft has a machined circular male lip that fits into an equally machined female recess on the flange on your differential. There are two different diameter lips depending on the drive shaft and differential. Be sure to check this before installing everything into the car. I discovered today that I need to swap the flange from my old diff onto my new diff. This should be pretty easy to do but it did add another small issue to have to work and will take a little extra time.

Be sure to make sure your shift linkage properly mates up with your transmission before you install everything into the car. I had troubles getting the shifter to properly mate up with the bushing on the end of the 'shift rod' (lack of better term) coming out of the transmission. I should have checked this before installing the tranny in the car. Basically the holes on the U-bracket at the end of the shift assembly were not concentric to the bushing. The top side did not line up and took a bit of work to open the hole to get a bolt all the way through. The stock Subaru bolt that goes in this location may have solved the problem I was facing. However, I didn't have that bolt and just ran a regular one all the way through and put a nut on the back side. It might actually be suggested to install your shift linkage to the 'shift rod' before dropping the transmission into place as you could shove it up into the cabin of the car from the bottom after the motor/tranny mount bolts are installed. It's a little tight and cramped down there to be playing around otherwise. Tight, but still doable though.

While many others probably already know this, you have to install the motor and transmission into the car with the transmission crossmember un-installed. Once you get the motor mount bolts to fall into the holes on the engine cross member you can install the tranny crossmember to the tranny and then place a jack under it and jack it up into place. This will let the motor mount bolts continue to fall down into the engine crossmember and it will get the tranny up into place to install the bolts through the tranny crossmember and into the chassis.

Another small note, on the WRX tranny you have to install a bolt/stud into the lower hole on the starter. The existing hole in the tranny will accept a tap for a 12x1.5 bolt very well. You can get a 12x1.5 bolt at NAPA for about $.50 and works great. You will need to drill out the lower hole on the starter but a 1/2in. bit makes quick work of this.


I think that's all I have to add to the thread tonight. Tomorrow I'm really hoping to tie it all up and be done with the swap. We'll see, hopefully all the issues are out of the way now though I'm not looking forward to swapping the flange on the diff. Thank goodness for air tools.

[skid542]

I'll get more details up tomorrow about tieing up the job.

For now though - it WORKS!!!!!

I drove it home from my friend's shop, about 35 mi., mostly interstate and had no problems. The clutch is going to take a little getting used to, and the lightweight flywheel too.

But the tranny feels like gold. Shifts are smooth but crisp. Everything just feels so good.

I'll get more details up tomorrow but I had to let the BBS know that it's a sucess (as of now at least, trying not to jinx it ).

A big thanks to everyone for all the help and patience in my relentless questions - Thank You!!

[n2x4]

Yeyyy. Good job. Enjoy shifting!

[Matt Monson]

Woo Hoo!

[GodSquadMandrake]

Congratulations! What are your impressions? Is it faster? Does it handle differently?

[skid542]

Well, it's been two days now and 150mi (mostly/all highway) later and I'm still in love with it.

I don't have much to report on performance as I'm just running wastegate boost until the clutch is broken in and even with that I'm not really getting on it. I will occasionally once the clutch is fully engaged, but no hard or fast shifting. I'll be reporting back once I get it broken in and really test it all out. I can say though, this morning I had to get around a couple of big trucks and down shifting into fourth at 65 felt great and power delivery was incredibly smooth - much better feel than the AT. 3rd gear highway passing will own though - can't wait .

That said, it's a remarkable step up in performance. The gear ratios are awesome and I can't wait to be able to hammer on it a little. The Grp N mounts have made a big difference in feel too. I know a lot of people have said this before me - but what a difference they make. It removes virtually all of the play out of the driveline, at my power levels at least. The connections between the gas pedal and the road is immediate.

Before I divert too much on the driving side of things I want to complete my notes on the build process.


The clutch system was still a PIA to install, even with the new MC. The 02' WRX MC has a bleed screw which really helped. First I installed everything into the car and then I put my electric vac pump on the slave and proceeded to pull three resevoirs full of fluid through it. I then did this to the MC. I tried the clutch - and nothing.

The trick I found (and a thanks to Matt for helping me find it), pump the system up so that the slave is extended out to where it needs to be and there's fluid in the line connecting the slave to the MC. Then crack the bleed screw and push the slave cylinder down as far as you possible can - a metal plate will help with this as pushing on that little pin can be uncomfortable.... Before letting up pressure, close the bleed screw. This will remove any air in the slave and the piston MUST be down in order for the bleed screw to be effective, otherwise the orientation of the slave will allow to sit up against the piston above the bleed screw. Now pump up the system again so that slave is back to where it needs to be. Next, bleed the MC like you would your brakes - have a helper open it and push the pedal in, hold, close the bleed screw. Pump the pedal a few times to get more fluid back into the MC and bleed it again. Repeat this several times. This finally did it for us and I had a working clutch. We did try taking the spare cap for the old MC and putting an air fitting on it to pressurize the MC. This didn't work as the seal around the cap wasn't air tight and we likely just blew more air into the sytem. The idea of using a bike hose clamped around the resevoir would be a better idea.

I will note - I had to trim the carpet and the sound deadening material under the clutch a fair bit. It looks a bit rough under the pedal and you can now see the bare chassis (well painted chassis). Over the years the sound deadening rummber had developed a large bump that interferred with pushing the clutch all the way down. Engagement is towards the end of the stroke and is not like the cable clutches I'm used to. Engagement is good, but you do have to have room to shove the pedal all the way down.


One part I discovered I needed and I don't recall seeing it on any of the other BOMS floating around on this conversion (sorry if I missed it) - you need the flywheel bottom cover plate from a MT car. The AT tranny has this cover as being part of the transmission and it will not work to swap over to the MT. If you don't put this plate on you leave the bottom part of the flywheel exposed and open for dirt/debris to get into the flywheel/clutch mechanism. I happen to have on of these on my old engine from my last BC (my old BC now lives on through parts - also stole a couple of flywheel/crank bolts - yay!). The part is small, but worth having if you intend to drive on public roads.

The final electrical work of the swap really is pretty simple. If your tranny was like mine in that my 5mt didn't have a 4pin connector but instead had (2) 2pin connectors then I wouldn't solder anything until you're sure it all works. The reverse and neutral switch on the tranny can be difficult to sort out as they both close when in reverse so ultimately I just tried one and then the other and walked around to the back of the car to see if the lights lit up. It must all be right though as now my reverse lights work and my handy VRG3 scan tool says my neutral switch is on when I'm in neutral and off when I'm not.


I did have one issue the first night by the time I got back to my house - the idle was too low. Basically the car would die out sitting at a stop light. I contribute this to the lightweight flywheel and the ECU trying to re-learn it. I first adjusted the throttle stop screw (if you do this - note where it was before you mess with it because you'll likely need to take it back to home position). This kept the idle high and kept the car from dieing. However, I must have opened it too much and it kept the TPS from closing far enough to trigger the ECU to turn the idle switch on. So my idle went from a little high to way too high (1.5k-2k). So yesterday evening I turned the stop screw back to home and my idle is back to where it should be and the ECU seems to have figured it all out. I will say though, if I have my heater on at idle it still tries to kill the motor - though not as severe. I suspect with some more driving the ECU will sort itself out, if not then I just get in the habit of turning the heater off at a stop light - it's not like the car dies immediately, you have a little time to realize what's happening.

Other than the idle issue though, it's great. I am really enjoying the lightweight flywheel and I accidently let the clutch out a little faster than I wanted to and the car just shot off the line. Launching will be fun when the time comes .


Like I said, I'll be reporting back with road/racing test results soon once the clutch is broken in and I've had a chance to wring it out a bit.

And again, thanks to everyone. My car feels like a brand new machine now and finally feels like the car it was meant to be.

[wtdash]

WELL DONE!

Have too much fun!

[Legacy777]

Congratulations.

Did you change ECU at all?

What did you do with the MT/AT ident pin?

[skid542]

Thanks guys. So far it's still running pretty well - outside my coolant expansion tank finally cracking a nipple Sat. (hooray!) So I'm taking the time to re-route a few lines to clean everything up a little while the RTV is drying on the brass fittings....

But to answer your question Josh, I didn't do anything to the ECU except snip the wire. My scan tool says the ECU now believes I have a manual tranny. So I'm happy .

[Legacy777]

good deal.