AT to MT swap. Helping clear the fog surrounding the parts that are required.
01-23-11, 09:30 AM
#1
AT to MT swap. Helping clear the fog surrounding the parts that are required.
Yep another thread about the swap. I did it back in 07 and have had no problems since. This is simply here to help some of the people who have PM'd me since. It's by no means perfect but it's just for the discussion of the swap and if anyone else can use the information. Instead of keeping the discussions in private I decided to bring it out for discussion should anyone have problems they might get a answer from my thread.
This is assuming you have a basic understanding of how to work on your car. You have the basic tools and some basic knowledge of how things work. The other 5 speed swap threads have almost all of the bolt sizes you'll need and combined with my thread maybe you can understand the differences of all of the strange new parts you'll be buying. I just simply want to help clear the fog surrounding the swap so that anyone interested can have their questions answered.
I guess I'll start out with just a list of parts you'll need if you had a running car. There are two ways to do the manual swap. You can do the cheap route without changing all of the harnesses, or you can go the expensive route, changing all of the harnesses. I went both ways, I got it running the cheap route, then later converted it to the expensive route because I wanted a car that no one could tell was swapped (newer auto harnesses are hard to find also). Now this brings up the question of whether or not I swapped clusters, at first I just kept the auto cluster as it's difficult to see the shifter indicator when it’s not in use. Later on I found a 5 speed cluster for cheap and just put that in for looks.
Parts list:
Manual transmission
Bolts for the bellhousing to engine, these are slightly different sizes than the automatic ones.
Clutch: pressure plate, friction plate, throw out bearing, pilot bearing & seal
Clutch bolts, use high grade bolts or call Mazda for these.
Flywheel, if you go lightweight get the flywheel and an auto counterweight. I’ll discuss this more later.
Get some flywheel bolts, again high grade or call Mazda.
Driveshaft from a manual
Rear pinion yoke for the manual transmission
Driveshaft bolts for the yoke, these are special bolts so make sure they’re the right ones. I think you can reuse the automatic ones.
Master cylinder for clutch, slave cylinder for the clutch, hard lines and soft lines
Shifter, shift **** and shifter boots (one leather, one rubber)
Manual pedal assembly
Manual starter
You can reuse your automatic ECU or buy a manual ECU. The only difference is that the hold light will be flashing if you reuse your automatic and you'll have a lower redline. I just swapped mine out since manual ECU's are so cheap. Hell I have 5 of them now, I don't even know where they came from! They just reproduce in the parts bin apparently.
And maybe some other small parts but this is a must have list.
Optional parts (expensive/time consuming route, also called proper swap):
Wiring harnesses, front main (ring) harness, engine harness, battery harness (power), and the dash harness. These all need to be from the same year manual car as you have. They have small differences but I don’t know exactly what they are. I tried using a 94 ring harness and my cooling fans no longer worked without turning on the A/C. I later swapped in the 93 harness and everything worked fine. This could have been a wiring problem I caused or the harness had but I just don't want to chance it with the price that these harnesses cost.
Cheap (aka basic) route:
Make sure you have all of your main harnesses in good working order from the automatic. You don't want to have any split or damaged wires/connectors because this will blow your engine or simply just drive you insane chasing problems. I found out the hard way, it blew my engine. If all of your harnesses are in good working order, you can simply start to compile parts to attach to an automatic motor or find a manual motor. The difference is that the rear plates are different, the manual has the starter on the transmission but the automatic has the starter on the rear iron facing towards the front of the car.
If you get a manual motor you’ll need to find a stock flywheel or if you go lightweight you'll need a rear balancer from the automatic to attach your new lightweight flywheel to the engine with. They're all the same weight so it's not anything super crazy to think about, just bolt it up and go. Then you attach your clutch and replace the pilot bearing inside the e-shaft, it's the small hole in the middle. You'll need a blind hole pilot bearing puller to get it out, there is simply no other way to get it out. Don’t forget to get a new pilot bearing seal.
You can then start to assemble the motor together bolting up the wiring harness, intake, vacuum maze, coils, alternator, water pump, etc etc. There are two ways to attach the motor to the transmission. You can do it inside the car with the transmission already hooked up to the rear of the car, or you can do it outside the car and slide both in at the same time and bolt the diff stuff up then. If it’s the first time doing it I’d recommend the transmission hooked up outside the car. Once you get more familiar with the car it’s much easier to do the transmission separate from the car (in my opinion).
Attaching the transmission to the car is simple if you aligned your clutch with an alignment tool, you simply slide the transmission into your new pilot bearing hole and bolt it up. You should then look up from the small hole in the bottom of the transmission and see a collar on the pressure plate of the clutch that you can pry backwards while pressing the throw out forward with your hand in the clutch fork (clutch slave area) and get the two to interlock. This is how the clutch works and it’s important to do it good but do not apply insane force to the locking collar, it can break that just means you take the trans back off and put it back together usually. After this point you can make a jumper wire to test your engine once it’s in or just make it permanent but you connect the two large wires in the main transmission harness part with a jumper cable, it’s pretty obvious which two wires once you get in there.
Now you attach the slave cylinder to the transmission bellhousing with the adapter that is usually on the transmission. Then connect the soft line to the slave cylinder, then the soft line to the hard line that attaches to the firewall, then the hard line to the master clutch cylinder then the master clutch cylinder to the master brake cylinder for fluid. It’s probably easier once you get in there and see what I’m talking about but I don’t know.
The driveshafts are different between the automatic and manual car, I’m not sure how much but I simply just bought a new one because I was in a rush. I never compared them so I have no idea how big the difference is. The main difference I saw is that the rear differential housing has a different bolt pattern than the automatic and you have to change the pinion yoke on the rear to a manual one to bolt the driveshaft up to it. It’s important to swap this piece because it can cause out of balance rotation and this can cause everything to explode while at speed. Don’t drill this out unless you’re filling lucky. I’ve seen success both ways but it’s more likely with replacing it with the manual parts. It’s simply just one HUGE bolt to take the automatic one out of the rear end. I think it’s a 27mm but don’t hold me to it.
At this point I believe you should have the engine and transmission bolted up inside the car. You can fill the transmission up with fluid, fill the shifter area with fluid, and put the shifter in. Then you can swap pedals out if you haven’t already. Then you can finish assembling the engine and what not.
Expensive (aka Proper) Route:
You change all of the harnesses in the front of the car. This includes the dash harness(this can be a two piece harness if taken out wrong so make sure you get both pieces), the front main ring harness, the engine harness, the battery harness (also called power harness). This is not only the expensive route but it’s also a very time consuming route. It took me a little over a week to get this completed. You’ll have to remove the dash, the fenders, the front bumper, the headlights, and a few other parts to get the main harness out. The rest of the harnesses you can be the judge of how to R/R.
Now I might have missed some parts or a few steps but hopefully you've combined this thread with a few other guides to get a idea of what all is required. Just ask a question here if you ever get stuck and I'll try to answer them all. Good luck
Some helpful threads:
Auto to manual swap, very detailed assembly guide: https://www.rx7club.com/3rd-generation-specific-1993-2002-16/93-fd3s-auto-manual-swap-step-step-925872/
FAQ for 3rd gens, aka every question ever asked: https://www.rx7club.com/3rd-generation-specific-1993-2002-16/faq-3rd-gen-other-useful-links-68640/
This is assuming you have a basic understanding of how to work on your car. You have the basic tools and some basic knowledge of how things work. The other 5 speed swap threads have almost all of the bolt sizes you'll need and combined with my thread maybe you can understand the differences of all of the strange new parts you'll be buying. I just simply want to help clear the fog surrounding the swap so that anyone interested can have their questions answered.
I guess I'll start out with just a list of parts you'll need if you had a running car. There are two ways to do the manual swap. You can do the cheap route without changing all of the harnesses, or you can go the expensive route, changing all of the harnesses. I went both ways, I got it running the cheap route, then later converted it to the expensive route because I wanted a car that no one could tell was swapped (newer auto harnesses are hard to find also). Now this brings up the question of whether or not I swapped clusters, at first I just kept the auto cluster as it's difficult to see the shifter indicator when it’s not in use. Later on I found a 5 speed cluster for cheap and just put that in for looks.
Parts list:
Manual transmission
Bolts for the bellhousing to engine, these are slightly different sizes than the automatic ones.
Clutch: pressure plate, friction plate, throw out bearing, pilot bearing & seal
Clutch bolts, use high grade bolts or call Mazda for these.
Flywheel, if you go lightweight get the flywheel and an auto counterweight. I’ll discuss this more later.
Get some flywheel bolts, again high grade or call Mazda.
Driveshaft from a manual
Rear pinion yoke for the manual transmission
Driveshaft bolts for the yoke, these are special bolts so make sure they’re the right ones. I think you can reuse the automatic ones.
Master cylinder for clutch, slave cylinder for the clutch, hard lines and soft lines
Shifter, shift **** and shifter boots (one leather, one rubber)
Manual pedal assembly
Manual starter
You can reuse your automatic ECU or buy a manual ECU. The only difference is that the hold light will be flashing if you reuse your automatic and you'll have a lower redline. I just swapped mine out since manual ECU's are so cheap. Hell I have 5 of them now, I don't even know where they came from! They just reproduce in the parts bin apparently.
And maybe some other small parts but this is a must have list.
Optional parts (expensive/time consuming route, also called proper swap):
Wiring harnesses, front main (ring) harness, engine harness, battery harness (power), and the dash harness. These all need to be from the same year manual car as you have. They have small differences but I don’t know exactly what they are. I tried using a 94 ring harness and my cooling fans no longer worked without turning on the A/C. I later swapped in the 93 harness and everything worked fine. This could have been a wiring problem I caused or the harness had but I just don't want to chance it with the price that these harnesses cost.
Cheap (aka basic) route:
Make sure you have all of your main harnesses in good working order from the automatic. You don't want to have any split or damaged wires/connectors because this will blow your engine or simply just drive you insane chasing problems. I found out the hard way, it blew my engine. If all of your harnesses are in good working order, you can simply start to compile parts to attach to an automatic motor or find a manual motor. The difference is that the rear plates are different, the manual has the starter on the transmission but the automatic has the starter on the rear iron facing towards the front of the car.
If you get a manual motor you’ll need to find a stock flywheel or if you go lightweight you'll need a rear balancer from the automatic to attach your new lightweight flywheel to the engine with. They're all the same weight so it's not anything super crazy to think about, just bolt it up and go. Then you attach your clutch and replace the pilot bearing inside the e-shaft, it's the small hole in the middle. You'll need a blind hole pilot bearing puller to get it out, there is simply no other way to get it out. Don’t forget to get a new pilot bearing seal.
You can then start to assemble the motor together bolting up the wiring harness, intake, vacuum maze, coils, alternator, water pump, etc etc. There are two ways to attach the motor to the transmission. You can do it inside the car with the transmission already hooked up to the rear of the car, or you can do it outside the car and slide both in at the same time and bolt the diff stuff up then. If it’s the first time doing it I’d recommend the transmission hooked up outside the car. Once you get more familiar with the car it’s much easier to do the transmission separate from the car (in my opinion).
Attaching the transmission to the car is simple if you aligned your clutch with an alignment tool, you simply slide the transmission into your new pilot bearing hole and bolt it up. You should then look up from the small hole in the bottom of the transmission and see a collar on the pressure plate of the clutch that you can pry backwards while pressing the throw out forward with your hand in the clutch fork (clutch slave area) and get the two to interlock. This is how the clutch works and it’s important to do it good but do not apply insane force to the locking collar, it can break that just means you take the trans back off and put it back together usually. After this point you can make a jumper wire to test your engine once it’s in or just make it permanent but you connect the two large wires in the main transmission harness part with a jumper cable, it’s pretty obvious which two wires once you get in there.
Now you attach the slave cylinder to the transmission bellhousing with the adapter that is usually on the transmission. Then connect the soft line to the slave cylinder, then the soft line to the hard line that attaches to the firewall, then the hard line to the master clutch cylinder then the master clutch cylinder to the master brake cylinder for fluid. It’s probably easier once you get in there and see what I’m talking about but I don’t know.
The driveshafts are different between the automatic and manual car, I’m not sure how much but I simply just bought a new one because I was in a rush. I never compared them so I have no idea how big the difference is. The main difference I saw is that the rear differential housing has a different bolt pattern than the automatic and you have to change the pinion yoke on the rear to a manual one to bolt the driveshaft up to it. It’s important to swap this piece because it can cause out of balance rotation and this can cause everything to explode while at speed. Don’t drill this out unless you’re filling lucky. I’ve seen success both ways but it’s more likely with replacing it with the manual parts. It’s simply just one HUGE bolt to take the automatic one out of the rear end. I think it’s a 27mm but don’t hold me to it.
At this point I believe you should have the engine and transmission bolted up inside the car. You can fill the transmission up with fluid, fill the shifter area with fluid, and put the shifter in. Then you can swap pedals out if you haven’t already. Then you can finish assembling the engine and what not.
Expensive (aka Proper) Route:
You change all of the harnesses in the front of the car. This includes the dash harness(this can be a two piece harness if taken out wrong so make sure you get both pieces), the front main ring harness, the engine harness, the battery harness (also called power harness). This is not only the expensive route but it’s also a very time consuming route. It took me a little over a week to get this completed. You’ll have to remove the dash, the fenders, the front bumper, the headlights, and a few other parts to get the main harness out. The rest of the harnesses you can be the judge of how to R/R.
Now I might have missed some parts or a few steps but hopefully you've combined this thread with a few other guides to get a idea of what all is required. Just ask a question here if you ever get stuck and I'll try to answer them all. Good luck
Some helpful threads:
Auto to manual swap, very detailed assembly guide: https://www.rx7club.com/3rd-generation-specific-1993-2002-16/93-fd3s-auto-manual-swap-step-step-925872/
FAQ for 3rd gens, aka every question ever asked: https://www.rx7club.com/3rd-generation-specific-1993-2002-16/faq-3rd-gen-other-useful-links-68640/
01-25-11, 04:49 PM
#7
Thanks guys, I just hope it's helpful to people who are looking into swapping transmissions out. There wasn't much information when I first started mine and I went through a lot of trial and error getting everything to work without any bugs. I'm notoriously picky with the way my car runs and drives so I spent a lot of time figuring out the little things. Well as with any FD they still present problems but hopefully I can help with at least some of them!
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thanks
03-25-15, 08:46 PM
#9
I noticed this list doesn't include a rear subframe. I have been told by a few shops that you need the rear subframe to complete this. can someone WHO HAS ACTUALLY DONE THIS(Not people who read the threads) chime in with confirmation.
We are going to be taking this project on ourselves as we have the means and aptitude for such a project.
We are going to be taking this project on ourselves as we have the means and aptitude for such a project.
I am going to change my ring and pinion out from a 3.90 to a 4.10. I am too lazy to adjust my speedo and I want my speed reading to be accurate, lol.
03-26-15, 08:33 AM
#10
You do not need the rear subframe to do a 5 speed swap. To do it completely correct, you would need a 5 speed rear diff, but most replace the auto companion flange with a 5 speed companion flange.
I am going to change my ring and pinion out from a 3.90 to a 4.10. I am too lazy to adjust my speedo and I want my speed reading to be accurate, lol.
I am going to change my ring and pinion out from a 3.90 to a 4.10. I am too lazy to adjust my speedo and I want my speed reading to be accurate, lol.
I also kept the auto diff and just rotated my driveshaft 45 degrees and drilled the correct bolt pattern for the auto companion flange.
03-26-15, 05:41 PM
#11
You don't need a different rear subframe.
I've been told you can reuse the speedo gear from the auto trans if you keep the 3.90 gears to calibrate the speedometer accurately but the difference was so minimal (3mph at 70) I didn't bother.
I feel like I should also mention that the auto counterweight is already on the automatic engine if you don't change engines. The flex plate attaches to the counterweight in stock form. You can simply unbolt the flex plate and bolt your lightweight flywheel up. If you have an OEM manual flywheel, you will need to remove the auto counterweight to install the manual flywheel (a counterweight is built into the OEM manual flywheel). The nut to remove the auto counterweight is 52mm (1-1/16") in size and is usually pretty damn tight (300ft-lbs). Be careful you don't forget the keyway when you remove the counterweight, you'll have a lot of issues if you do.
I've been told you can reuse the speedo gear from the auto trans if you keep the 3.90 gears to calibrate the speedometer accurately but the difference was so minimal (3mph at 70) I didn't bother.
I feel like I should also mention that the auto counterweight is already on the automatic engine if you don't change engines. The flex plate attaches to the counterweight in stock form. You can simply unbolt the flex plate and bolt your lightweight flywheel up. If you have an OEM manual flywheel, you will need to remove the auto counterweight to install the manual flywheel (a counterweight is built into the OEM manual flywheel). The nut to remove the auto counterweight is 52mm (1-1/16") in size and is usually pretty damn tight (300ft-lbs). Be careful you don't forget the keyway when you remove the counterweight, you'll have a lot of issues if you do.
Last edited by Copeland; 03-26-15 at 06:45 PM.
03-26-15, 10:55 PM
#12
I read from the FSM and was told that when swapping the companion flange on the auto diff that the pre-load is important to get right when tightening the Flange nut on the new manual flange. How many have done this themselves with no issues? I've heard of diffs failing/exploding as a result.
03-27-15, 05:47 PM
#14
I read from the FSM and was told that when swapping the companion flange on the auto diff that the pre-load is important to get right when tightening the Flange nut on the new manual flange. How many have done this themselves with no issues? I've heard of diffs failing/exploding as a result.
The cluster is purely cosmetic, definitely optional. Thanks - I wrote this a long time ago and still remember the swap pretty well hah. The car sure has changed a lot since 2011...
Last edited by Copeland; 03-27-15 at 05:53 PM.
