DIY Honda Civic 5-Speed Conversion

[DaX]

Well, I figured I'd start a new thread for this, since I'll be getting started on it this weekend. This thread will document the process of my DIY 5-speed covnersion from an automatic transaxle in my 1990 Honda Civic DX. First I'd like to say that this project becomes much more difficult (that I am aware of) if you leave the 1988-1991 Civic realm. I know for a fact that if you do this on a 1992-1995 Honda Civic, you have to drill spot welds and move a welded drivetrain mounting bracket on the car's frame.

As a history, you can click HERE to see my DIY on a manual pedal cluster install, and HERE to see my DIY on a CRX HF transmission overhaul. I'm getting my background for this DIY from many posts across many message boards, and THIS site as well.

05/29/06 - The car is down at my dad's house in the shop, awaiting saturday, when I'll start the process.

[thisisntjared]

this really makes me appreciate owning an eg...

[MetroMPG]

Another tranny swap thread. I like it. Good luck, DaX.

Care to give us some background on the different gears/final drive numbers involved?

[DaX]

Originally Posted by thisisntjared

this really makes me appreciate owning an eg...

Why? Because it's more difficult to do a 5-speed conversion on them?

Originally Posted by MetroMPG

Care to give us some background on the different gears/final drive numbers involved?

Sure. The reason I'm doing this conversion is - (a) I love driving a 5 speed and (b) I'm hoping the longer gear ratios from the HF transmission will allow me to get more gas mileage by maintaining lower engine RPM's at constant speeds. This will help me (in theory) as > 80% of my driving is highway @ sustained speeds.

The gear ratios in my HF transmission are as follows:

1 3.250
2 1.650
3 1.033
4 0.823
5 0.694
R 3.153
FD 2.95 (non-California model)

I have verified this by counting teeth on the gear sets while I was rebuilding the transmission, but I seem to have misplaced the sheet where I wrote the actual gear teeth numbers down at.

I do not know what the gear ratios are for a 1990 Civic DX with an automatic transmission, but perhaps someone else can give insight into that (SVO?).

This will be my first time attempting the conversion, but I don't think it will be that hard after reviewing the limited information available. I still haven't decided whether or not I'm going to pull the entire engine/tranny or just the tranny. Pulling the entire setup isn't necessary (it is more work), but it will yield more room. I'll probably end up yanking the whole thing.

Basically, the parts I have collected for this conversion are: CRX HF transmission, D-series flywheel, stock Exedy replacement clutch kit, Clutch cable, engine mounts from a civic with a manual transmission, an ECU from a manual equipped civic (DPFI), and a shift linkage from a 1988 Civic with shift boot & shift knob.

I have already rebuilt the transmission with new bearings and seals. I opted not to replace the synchros for money reasons (it would have been an additional $250 for parts) and because people rarely abuse HF transmissions - I'll admit I'm taking a chance on this, but it's a calculated risk. If necessary I'll pull it back out and throw in new synchros at a later date. I have also already installed my manual pedal cluster over a year ago. It's been weird riding around with a dead pedal, especially when going from my manual 1988 Civic to this auto 1990 Civic.

It's a pretty direct swap, all in all. There is some wiring necessary for the reverse lights (on an auto, the reverse light switch is located at the shifter console, and on a manual, it is locate on the transmission) and for the park lockout. The latter is a mechanism on automatic cars that prevents the key from being removed from the ignition unless the car is in park. Wiring is simply needed to fool the car into thinking it's always in park. I will need to cut a hole in the center tunnel for the shift linkage to poke through. Eventually, I would like to acquire the proper piece of sheet metal from a manual equipped Civic and weld this in place - this will cut down drastically on road noise and wind entering the cabin, as the sheet metal has a lip that allows a rubber boot to seal the cabin.

Anyhow, sorry to be so wordy. This weekend will mainly focus on getting the tranny (or engine/tranny) out, moving the mounts around, and getting the manual transmission bolted to the engine.

[MetroMPG]

Originally Posted by DaX

Anyhow, sorry to be so wordy.

No, don't apologize! That's good info. Thanks for the backgrounder.

So it's the same transmission that Ben just installed?

[MetroMPG]

Originally Posted by DaX

Anyhow, sorry to be so wordy.

No, don't apologize! That's good info. Thanks for the backgrounder.

So it looks like the same transmission that Ben just installed. Is that the tallest tranny option that fits your engine?

[DaX]

Originally Posted by MetroMPG

No, don't apologize! That's good info. Thanks for the backgrounder.

So it looks like the same transmission that Ben just installed. Is that the tallest tranny option that fits your engine?

I believe so. Here's a comparison of the HF tranny to the VX tranny, which are the two tallest transmission options available for D-series engines (I think):

-----VX------HF--
1---3.250---3.250
2---1.761---1.650
3---1.066---1.033
4---0.853---0.823
5---0.702---0.694
FD--3.250---2.950

I also forgot to mention that I plan on attempting to fix the air conditioning while I have the car in the shop.

[thisisntjared]

Originally Posted by DaX

Why? Because it's more difficult to do a 5-speed conversion on them?

err. i meant 'im glad i have a 5spd eg' i think they both have their ups and downs and it is more expensive to do a manual conversion on an eg, but there is a lot more room to move about.

to some extent i agree with taking the whole swap about of the engine bay. especially since you have a hoist.

i would rather do a swap than a auto-manual conversion. it seems like swaps take less time.

[DaX]

Originally Posted by thisisntjared

err. i meant 'im glad i have a 5spd eg' i think they both have their ups and downs and it is more expensive to do a manual conversion on an eg, but there is a lot more room to move about.

to some extent i agree with taking the whole swap about of the engine bay. especially since you have a hoist.

i would rather do a swap than a auto-manual conversion. it seems like swaps take less time.

I totally understand what you mean about the EH2. I really miss my EH2's sometimes, but as time progresses, I grow more and more attached to the ED6 bodystyle.

I agree with you on swaps taking less time - with all the right parts available, I can do a swap ALONE in one day. The more I think about it the more I'm leaning toward pulling the whole engine. It will also lead to better (less cluttered) pictures for the DIY.

[Matt Timion]

Awesome project. I was going to start my engine today, but we have family visiting this weekend and I need a four door car, so the engine swap is put off another week.

Is anyone driving through Utah next week for a few days next week and wants to get their hands dirty?

Anyone?

[MetroMPG]

There's another late-model Metro owner in SLC I've tried to get to join the board, Matt, but no luck yet. (He's a tinkerer too.)

This kind of stuff can go so much faster with 2 people working. I've found working on the ForkenSwift with Ivan we tend to motivate each other to be productive, and if we're smart enough to actually work on separate tasks rather than watch over the other guy's shoulder, the work actually goes more than twice as fast.

[thisisntjared]

Originally Posted by DaX

I totally understand what you mean about the EH2. I really miss my EH2's sometimes, but as time progresses, I grow more and more attached to the ED6 bodystyle.

i think the ed6 takes an aquired taste. when i first got into hondas i didnt like the crx's or efs. my dad offered to buy me one for cheap, but i decided to hold out for the more expensive eg.

in hindsight, i shouldve just taken the ef.

i would love to have the d16z6 in a gutted rex....

anyway, are you going to maintain powersteering and airconditioning? or is there either in your car. that would be my deciding factor of pulling the engine out.

[SVOboy]

Dax, let us not forgot the CX and the VX are the same tranny.

More love for my tranny, woo. I'll say some nice things about it in a new thread soon.

[thisisntjared]

im kinda annoyed with the cx tranny... and all of the longer geared trannies. all of the gears except first and 5th are stretched out, which is totally fine for fuel economy while accelerating. however i feel it defeats the purpose for highway driving when 4th gear is longer but the difference to fifth is minimal.

the z6 tranny makes a point to space out 4th and 5th and with the cx/vx final drive would be more ideal. the right thing to do would be to just make the 5th longer...

[SVOboy]

The right thing to do, hehe.

I'm glad dax is doing the write up so I don't have to.

Dax, is there anything you want me to do for you on this note in terms of writing/pictures?

[DaX]

Originally Posted by thisisntjared

anyway, are you going to maintain powersteering and airconditioning? or is there either in your car. that would be my deciding factor of pulling the engine out.

I plan on maintaining both...er...fixing my AC and keeping the power steering. It's still pretty easy to pull the engine while leaving both of these systems in tact. I'll detail it in the DIY.

Originally Posted by SVOboy

Dax, let us not forgot the CX and the VX are the same tranny.

Oh yeah, I totally forgot that these two trannies were the exact same. Thanks for pointing that out!

Originally Posted by SVOboy

Dax, is there anything you want me to do for you on this note in terms of writing/pictures?

Nah, not at this point anyhow, but thanks!

[SVOboy]

Eh, I'm useless.

[DaX]

Well, I started the conversion on Saturday. I'm over halfway done, and the only reason I'm not done is because the stinking Machine Shop was closed Sunday so I have to wait to get my flywheel resurfaced.

I ended up pulling the entire engine/tranny...and I'm glad I did. I don't want to think of how hard changing the rear mount would have been with an engine in there!

My explanation may be a little more in depth than most would want, as I am a HUGE neat freak when it comes to wiring. Most if not all of the wiring for this conversion will be contained within the stock harness. I spent a long time yesterday tracing wires and unwrapping loom. I have the engine harness wired, and still have the chassis harness left to do. Don't let the difficulty of my way of wiring scare you away from this conversion...you can just run wires directly if that doesn't bother you.

Anyhow, we haven't hit any snags that have scared me yet. Changing the rear mount has been the hairiest part - we did have to loosen bolts and lower the rear cross member to get to one of the bolts, but it was no big deal (why is everyone, including me, so affraid of lowering cross members?).

While we have the engine out, I have decided to replace the front crankshaft seal, as I have been having oil leakage issues, and I'm pretty sure this is the culprit. There will be a short segment of photos documenting this as well.

I'm so excited to get this conversion finished...I can't wait to drive my car! I have taken LOTS of pictures, but I left my camera down at my dad's house, so I won't be posting pictures until I'm finished.

[SVOboy]

I def wanna see some write up on the crossmember!

[DaX]

Comments are BELOW the pictures.

Wiring convention: If the wire is stated as a single color, that is the only color of the wire. If the wire is stated as two colors (ie - YEL/BLK), the first color is the primary color of the wire and the second color is the color of the stripe.


Remove hood. Do not disconnect the battery yet!!!!


Remove the center console cover to expose the shifter. Two phillips head screws on the sides hold the shifter handle in place - remove the shifter handle. Four phillips head screws (you can see them here...they're gold) hold the shifter faceplate in place - remove them and the shifter face plate.


There are three plugs that need to be unplugged - a 10-pin plug, a 2-pin plug (large gauge wires), and another 2-pin plug (small gauge wires).


As oriented in the photo above on the 10-pin plug, remove the two wires on the top row (closest to the clip) all the way to the right (as viewed above from NON-wire side). The wire colors are BLK and GRN/WHT


Solder these two wires together. This will make your car think it is in park all the time. To verify that you have connected the correct wires (this is also how I figured out which ones to connect), turn the key in your car to the on position (2). The gauge cluster should show that the car is in park (P will be lit), even with the plugs disconnected from the shifter. Turn the car off and put tape/heat-shrink over your solder job.


I had already put a 5-speed cluster in my car, so I took this part out of my old auto cluster and plugged it in. You can see that the P would be lit on the cluster, regardless of what position the shifter is in.


Back at the shifter, cut the plug off the 2-pin plug with large gauge wires (BLK/WHT). Solder these two wires together and put some heat shrink over the connection. This will allow the starter to get the 12V it needs to start the car. Once you've done this, you can go ahead and start pulling the engine and tranny.


Dad gets to work removing the axles (be sure to drain the tranny fluid before you pull the axles)...


...while I get to work disconnecting the automatic shifter cable from the transmission. To disconnect, put the shifter in the neutral (N) position. Get under the car and remove the sheet metal access plate (sometimes called the flywheel plate) to expose the torque converter. Once you can see in there, you'll need needle nose pliers (and lots of patience) to pull out a cotter pin. Once the cotter pin is off, a small metal clip comes out and the cable comes off. Don't forget the 12 mm bolt at the rear of the tranny that holds the cable sleeve on.


Unbolt and remove the auto shifter. There are bolts in the cabin and under the car that must be removed.


Drain all fluids - engine oil, automatic transmission fluid, and coolant. Be sure to do this before you pull the axles, or you'll have a mess on your hands.


Pull the radiator for clearance to get the motor out. Be sure to disconnect all electrical connections and all coolant and automatic transmission fluid connections before you start yanking. It's tough, but it will come out. Also unbolt the AC compressor from the engine (four 12 mm bolts) and zip-tie it out of the way.


Pull the motor. This is the proper angle when pulling from the top. I like to start with the engine balancer all the way to the left and chain it up where that is level. Then loosen all the mounts and crank the balancer all the way to the right...this gives the best angle for me every time. I went ahead and removed my front crossmember just for added clearance when pulling the motor. If you want to pull it, remove the front engine mount bolt, four bolts holding it to the frame, and four bolts holding it to the front lower control arms.


This is the rear engine mount. This is the whole reason why I pulled the motor too. The mount must come off. Three 12 mm bolts hold it on - one in front, two in back. I used 3/8" drive ratchet with 6" extension, universal joint, then a short well 12 mm socket to get the back bolts off. No sweat.


Another shot of my setup to get the back bolt off. You do NOT have to drop the rear cross member to remove the auto mount.


LEFT - manual transmission rear mount and bracket. RIGHT - auto transmission rear mount and bracket.


Rear mount removed. You can see there are four bolt holes, but only three bolts to hold the rear mount on. The back two holes are used for either the auto or manual mount. The front right bolt hole in this view is used for the auto mount. The front left bolt hole in this view is used for the manual mount. Be sure to use an appropriately sized tap to chase the threads in the front left hole before you put a bolt in - it's been exposed to the elements for over 20 years and could use some cleaning.


Install the manual mount. You MUST lower the rear cross member to do this. It's not as bad as it sounds, I promise. There are four bolts that hold the rear cross member to the car - two on each side. I unthreaded the bolts on the driver's side about halfway and completely removed the bolts on the passenger side. My dad put a little pressure on the cross member pushing it toward the front of the car, and I was able to slip my setup behind the mount and tighten the back bolts. After that I simply put the four bolts back in and tightened them up. The rear mount is IN.


Dad separates the auto tranny from the eingine. We spilled ATF everywhere - it started pouring out of the torque converter! Be ready to clean up a mess.


Remove the torque converter. It's a bunch of 10mm bolts. You have to loosen them from the area where the sheet metal access panel would go on the bottom of the engine. After that it pulls right off.


Unbolt the torque plate. It's six 17 mm 12-point bolts. I used an air impact wrench. These bolts are stamped "AT" for auto tranny. They will not work to bolt on a flywheel (too short). You need to get some flywheel bolts (stamped with "MT").


My rusty flywheel before resurfacing...


Freshly resurfaced flywheel. Be sure to take out the old pilot bearing before you take it to get resurfaced.


Use a seal/bearing driver to install the new pilot bearing that came with your clutch kit. It gets hammered in from the back side.


Pilot bearing installed. Make sure it is all the way in!

[DaX]

Damn! This weekend is father's day, so I don't know if I'll be able to work on it any more this weekend. Maybe I can get some time in on Saturday.

[Matt Timion]

Holy crap... very detailed. Looks like I need to go back to the junkyard and try to get SVO the section of the rear mount that goes on the crossmember as well. I only got him the part that attaches to the transmission.

Hopefully I can do it without removing the crossmember. Ugh.

[SVOboy]

You should be able to remove the mount without dropping the crossmember, I did.

Anyway, I'm still not sure if I need it, since most people say you do not, so, I dunno, I'll try and figure that out.

[Matt Timion]

Originally Posted by SVOboy

You should be able to remove the mount without dropping the crossmember, I did.

Anyway, I'm still not sure if I need it, since most people say you do not, so, I dunno, I'll try and figure that out.

I didn't get it because I didn't have my swivel socket thingie with me.

I did, however, get 4 TPS sensors and an optional audio console for a blue sedan

Cha-ching!

[DaX]

Originally Posted by SVOboy

You should be able to remove the mount without dropping the crossmember, I did.

I don't know man...it looks like it's about 1" or more off from the automatic mount.

Originally Posted by SVOboy

Anyway, I'm still not sure if I need it, since most people say you do not, so, I dunno, I'll try and figure that out.

If you read, I was able to remove the auto mount w/o dropping the x-member too. Installing the manual mount was different. All the heater core plumbing is in the way, and I am VERY weary of removing 18 year old heater core componets, as I have personally wrecked one just by touching it. If you have the balls, you can probably remove this stuff and avoid having to drop the x-member...but it's so not worth it - dropping the x-member was a breeze and made everything work out great.

[jpciii]

great write-up, man... keep it comming

BTW, that site you posted is just like this one http://rywire.com/store/auto2man.php


I wonder which one is the original...

[DaX]

Originally Posted by jpciii

great write-up, man... keep it comming

BTW, that site you posted is just like this one http://rywire.com/store/auto2man.php


I wonder which one is the original...

Hmm...that's odd. I wonder if the AOL site I posted belongs to Ryan, or if Ryan just got permission from the owner of the AOL site.

I may try to get my wiring completed on Saturday, with lots of pictures of course. I don't think I'll have it all together by this weekend, as I'm going to have to drop off the flywheel at Zappa's on Saturday and may not be able to pick it up until Monday.

[90CivicStandard]

Looks great!

I love reading detailed write ups like this!

Good luck with the rest of it.

P.S. I didn't have to drop my rear cross member to add the mount either. But I don't remember how I did it, I just remember not having to. Anyays... also, why did you remove the axles? I always just leave them connected to the hubs and pop them out of the tranny.

[DaX]

Originally Posted by 90CivicStandard

why did you remove the axles? I always just leave them connected to the hubs and pop them out of the tranny.

It only takes a few extra minutes to take the axles all the way out...I like having LOTS of room to work with.

[DaX]

Worked on the car more today. Got the flywheel resurfaced, pulled the dash out, and finished my wiring. I'll post pictures sometime this week. One more day of work and I should have it all back together. I'm excited to see how much of an FE improvement this will be!