IMPORTANT, IF YOU DO NOT HAVE THE ABILITY OR UNDERSTANDING TO REMOVE AN ENGINE AND A TRANSMISSION, YOU WILL NOT BE HELPED BY THIS INFORMATION, THIS INFORMATION REGARDS PROBLEMS THAT WILL BE ENCOUNTERED DURING AN AUTO TO MANUAL SWAP
THE FOLLOWING WILL/MAY BE LOST DURRING A CONVERSION
ABS (believed to be solved by retaining the TCU and using a resistor to give the TCU the illusion of being in neutral, this doesnt solve cruise control) read more here Legacy Central -- Transmission Conversion and here '98 RS 4EAT to 2000 RS 5MT w/ LSD - NASIOC
*CREDIT!* I recieved a large amount of technical and mechanical help From SleepySubie on my project, All credit goes to him, I provided the garage and the budget for this learning experience. *CREDIT!*
This covers an RS Transmission swap, more specifically a 98 RS Auto to a 2000 RS Manual,
Step 1: Parts collection (the following is specific to my situation, specifics may vary without notice)
Manual Transmission (including mounts)
Matching Shifter Linkage (includes bushings/nuts bolts ect.)
Matching Shifter (Ensure that you have ALL bushings and screws)
Matching Flywheel and Clutch/Pressure Plate
Matching Clutch (master and slave) and Pedals *NEED CONFIRMATION, on brake pedal engage switch*
Matching Manual Starter
Manual Drive shaft
Manual Rear differential (be sure to match gear ratios, consider this a great time to upgrade to LSD)
Manual ECU Not Required but fuel maps are different between the two. (Same year/trim as your vehicle RS gets RS, L gets L, WRX gets WRX)
your model/trim shifter trim and shift knob (Auto shifter trim offers enough clearance for proper shifting with a short shifter without modification)
We used the 98 RS Automatic CV Axels for both front and rear, if you check with any retailer of rebuilt or oem replacement parts they tend to use the same part number for both auto and manual variants, which could show either that these parts are the same or that these retailers dont care, I'm going with the first as the 2000 rs axels appeared identical to the 98's (in the rear, the fronts had the ABS ring on the axel vs on the hub no spline additions or extras aside from that) they will how ever charge extra for one or the other left or right on the LSD rear axels, but we couldnt order either to be sure since none of the retailers had any in stock or capable of being ordered.
!!!! If you collect a transmission from a year/model that is not of your own, such as in my case where I purchased a 2000 RS transmission for my 98, you MAY need to keep your speed sensor as the connector varies.
Step 2. Mechanical break down (Simple as dirt because this is covered in other DIY's in the forum)
remove the engine, trans, drive shaft and rear differential.
you will have to remove the shifter trim and seperate the automatic shifter from its arbetrary linkage, there will be a few bolts most likely stuck to some degree which you will need to seperate from the transmission, if you wish to sell it, you're gonna want to leave that sucker in tact. now, what you do with the shifter itself is up to you! As long as you leave the little clips with wires leading away from the shifter alone you will be fine.
Continue to split the Transmission from the engine if you didnt durring your original removal process.
At this point you can check your speed sensor on your transmission, if the replacement transmission has the same sensor you can keep it, if not, simply remove the old one from your automatic and put it in the manual trans.
If your automatic transmission is 98 or older, and your replacement transmission is 99 or newer you will notice that the transmission has 6 bolt locations wile your motor has 4.
This will cause no eminent threat to your project! it will cost you another 10-15 dollars. We had to tap a new hole into the starter and purchase a larger bolt to bolt the second end of the starter down, this also requires you to expand the hole on the 2000 MT5 Starter. This secures your starter properly and taping the whole larger doesnt hinder your future USDM WRX swap.
Obviously you will need to remove the torque converter and flex plate from your engine. and proceed to replace it with your matching clutch, pressure plate, and flywheel. You can now reattach your engine and transmission and put them back into the car. (If you haven't done this before, I suggest installing the starter after the engine/trans are securely in place, less to get caught on)
You will want to install the shifter linkage before you insert the drive shaft as its going to get in your way, kartboy bushings are great to do now rather than later. and since you're playing with it, go ahead and install the shifter. (leave the trim off till you're done)
Proceed to install the new rear differential and drive shaft, and reinsert the old axles (for the front, you may want to purchase new pins for the inner connection between the axles and transmission)
Step 3: Some assembly required
Now you're going to need to take apart the lower portion of your dash on the drivers side, and gain access to your ECU this will be under the passengers feet, covered by a metal kick plate.
Start by replacing the ECU (same years/trims will clip right in)
Next we will go over to the Pedal box
the pedals you should have purchased need to match your clutch cylinder, from my findings on the 98 (I haven't had the privilege to search other auto or mt5 vehicles other than my own and the donor car)
You will notice the TCU dangling there or bolted onto the Auto brake pedal, this has to be removed, but according to what I've read this controls your ABS system, removing it kills automatic ABS, one simple solution is to get a fully manual wiring harness, manual abs unit and controller. but that isn't so practical (unless you're doing a WRX swap in which case you really don't need to be reading this) regardless there is information about this problem at the top of the page to refer to, as information is found I'll add it to the DIY
IF I am assuming correctly, the manual brake pedal and auto brake pedal are the same, or I'm wrong and the 98 was wired for both pre and post brake pedal boxes either way you should get lucky and the connectors match or you have both in there, the clutch side on the other hand you wont be so lucky, you don't have a clutch switch. there are two options here. you will run a 12 gauge wire directly from the ignition to the starter (yes the starter on the transmission) OR you will run a wire from the ignition to the clip on the clutch pedal (standard spade connectors fit snugly) and run a corresponding one out, all depends on how much you trust yourself to start the car in neutral or with the clutch depressed.
Now for some more wire housekeeping, now if you return to your shifter area you will notice your funny little shifter wiring, ** due to me have lost the pictures I'll be blunt and explain till I get the visuals up** here you have 4 wires on one clip and two on the other, the 2 others light up an indicator to help you figure out what mode you are in, when its dark, its useless. the other 4 have a great purpose, 2 control a locking motor to keep you from exiting park wile the car is off and the other two dictate that it IS indeed in park, (this allows two things, ONE it allows you to take your key out, and two, it turns the fuel pump on, which is kinda important!), the simple mans way of doing it would simply be to take the two that activate the switch (easily known as the ones that DON'T go to the locking motor) and splice them together and retain the clip and plug it into the shifter harness and toss the shifter.
Finally we return to the engine bay, the following you will have to find wiring pin outs on your own, I will post the RS ones when I post the pictures
you will need the reverse lights, there is also the neutral position switch (I haven't looked it up but we believe its for cruise control which you cannot use any more), both send a signal, so one goes to ground one goes to the reverse light pin. best way to do this is to locate the Auto wires per those pins and splice them into the transmission sensor wires as you wouldn't want some one hitting you because your reverse lights weren't on. and that's it for wiring!
In a way you could almost say that you're done! BUT for obvious reason you will want to check and double check that all of your exterior lights are working as they should. Between now and when you turn the car on, please ensure you have emptied out and refilled both your differential and transmission with new fluid and unless you're crazy and lifted the engine with the radiator you're going to need to refill that as well.
And as per any DIY ESPECIALLY THIS KIND
I AM NOT RESPONSIBLE FOR ANYTHING YOU BREAK/SHORT/DESTROY DURING THIS PROCESS, OR ANY FAILURE OF THE VEHICLE DURING NORMAL OPERATION, NOR AM I LIABLE FOR YOUR VEHICLE IF ANY BREAKING SYSTEM FAILS AND/OR CAUSES AN ACCIDENT WHICH LEADS TO YOUR INSURANCE COMPANY REFUSING TO PAY DUE TO UNANNOTATED MODIFICATION OF YOUR BREAKING SYSTEM
****** I TYPED THIS ALL IN ONE SITTING I'M PROOFREADING IT AS WE SPEAK Images will be uploaded soon for now, here's a video of sleepysubie starting my car with no exhaust *****
Impreza 2.5 RS No headers - YouTube