CVT Destroyed at 45k, looking to MT swap

[Derek.]

Think of it this way:
Scenario A: If you replace the CVT transmission, you have a running car you can sell/trade for something with a manual transmission.

Scenario B: If at some point during the transmission swap, what happens when you run into issues with compatibility between parts? Get frustrated and want to quit? Realize that this is costing too much time/money to complete? You are left with a half-finished project, or a car that is put back together but riddled with problems. You'll have a real tough time trying to sell/trade that car.

Scenario C: Everything works 100% with the swap. Success! You'll probably shave a few years off your life and maybe invent some new levels of profanity, but SUCCESS!

I wish you the best in whatever direction you choose to take.

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[gtman]

Think of it this way:
Scenario A: If you replace the CVT transmission, you have a running car you can sell/trade for something with a manual transmission.

Scenario B: If at some point during the transmission swap, what happens when you run into issues with compatibility between parts? Get frustrated and want to quit? Realize that this is costing too much time/money to complete? You are left with a half-finished project, or a car that is put back together but riddled with problems. You'll have a real tough time trying to sell/trade that car.

Scenario C: Everything works 100% with the swap. Success! You'll probably shave a few years off your life and maybe invent some new levels of profanity, but SUCCESS!

I wish you the best in whatever direction you choose to take.

Sadly, those of us that have been there/done that (I've been modding cars longer than most of you have been alive) know that C is the least likely outcome. Unfortunately B is highly likely, making A the best/smartest/safest bet.

But again, there is nothing wrong with being a pioneer. At my own car forum, I was the first to do many mods that were then duplicated by members there.

With this transmission swap mod though, so much money has to be spent with absolutely no guarantees ...

If you can afford to do it, have a high tolerance for frustration, and this is a big goal for you... go for it. But if money is in any way tight, give it a bit more thought before jumping into the abyss.

 

[Derek.]

Sadly, those of us that have been there/done that (I've been modding cars longer than most of you have been alive) know that C is the least likely outcome. And unfortunately B is highly likely, making A the best bet.

I'm in that been there/done group with you lol. A little optimism never hurts.

 

[hobby-man]

OP is trying to build something that a Honda dealer would love to sell you with a 5 year warranty. I don't get it. At all.

This is where I'm stuck lol. I'd love to see K-swapped or LS-swapped hatchbacks all day. But even if this goes flawlessly, the best case scenario is you have one of a million 6MT hatchbacks on the road already.

 

[Shankmeyster]

Better to just trade for a manual Sport or Si and save the cash.

 

[Tony503]

OP, go for it! I did a AT to MT swap on my FR-S after someone else successfully did it and although it was frustrating at times and it took me 6 months from researching to turning the key, it was worth it considering all that I learned about the FR-S. Maybe I'll do it for my ST hatch someday too if you figure it out. Looking forward to your results.

 

[Nickthewaffler]

Steering Assembly matches, and so do the front knuckles. There are some wiring harness differences for wheel sensors, but that can be ordered after the swap if there is an issue. Having some trouble figuring out the wireless key entry. The si uses a computer module with a few antennas to pickup key signals. Has anyone done any work to these kinds of electronics and explain the situation?

I'm guessing the module connects to one of the wiring harnesses, probably the gauge cluster harness and doesn't allow for the car to start unless the antennas are providing it with the correct signal. Would there be a way around this while maintaining the keyed ignition? It's hard to tell from the diagrams online.

 

[Nickthewaffler]

I've ordered the following the things and some extra mounting clips/bolts in case:
Transmission, Change lever assembly and wire, clutch, flywheel, pedals, master cylinder/slave, MT sport hatch ecm, central half shaft, side transmission mount.

Sport hatch ecm, so that my key setup can be used. Not sure why I didn't think of this when considering purchasing an Si ecm.

Still confused why the power steering pumps are different from CVT to MT, but hopefully it's nothing too bad, the pumps are discontinued so I need to find a used one if that's the case.

If it goes bad, i'll need to order the rest of the axle assembly, engine and gauge wiring harnesses, and gauge cluster. The build linked earlier with the si tranny in a mt hatch, showed promising results on the axle.

I'll test fit items and plug in computer to see if car starts. If all is well, I'll take it to a garage with a lift and drop the tranny from the bottom, install the clutch and flywheel, replace the half shaft, and be golden. I have some confidence that the parts I ordered will be enough to get the car moving. I'll be expecting errors to come up in the ecm from having the incorrect gauge cluster, but hopefully not. I've checked all the electrical paths and there should be no reason for honda to use different wiring harness setups, but who knows, the part numbers are different.

That is a hopeful outlook, so I'll be in the mindset that catastrophe may be imminent. Parts should all arrive by the 20th, will be enjoying time at home in the meantime.

Honestly I scored pretty good deals on most of these parts, so I won't be too frustrated if all goes down. The race clutch and flywheel were the hardest swallow out of everything, and those will be the easiest to sell off to some civic guys I know, or at least I hope.




Edit: Also purchased engine wiring harness for 6sp hatch. The amount of money it costs vs the CVt harness is hard to explain so I will be safe.

 

[Tony503]

I believe Honda is known to have different part numbers just based on different suppliers, eg. I was looking at the center console cupholder insert and the part number for the hatch is different than the sedan/coupe but they should be interchangeable. On the other hand, some advice from my swap- the FR-S ABS module looks and works the same between the AT and MT versions but they have different firmware so that they're not interchangeable, so it could be something like that for the power steering pump, don't know how "smart" they are.

 

[Shankmeyster]

I don't know how a power steering pump could be discontinued on a vehicle that is still in production.

 

[Nickthewaffler]

Alright just a quick update.

Nothing major happening yet, but I thought I would log the progress here.

Day 1: Last night I needed to jump start the car. I cleaned it out and prepped a table with all the tools I had on hand. I also went to Auto zone and loaned out about $300 worth of axle disassembly tools. See pic.

Day 2: Brought some more tools and almost all of the parts have arrived. Si transmission came via fedEx today. Started disassembly of all the basics and draining the ATF today. Struggling with the axle nuts, I think I'm going to need a breaker bar. Will continue today if I can get my hands on one. See pics.

Still waiting for ECM, programming software, and shifter assembly(found a few on eBay with the wires so I canceled my first order. )

I talked to two very experienced custom-build mechanics, and they have few doubts that this project will fail, but they agreed that it wouldn't be easy. I have their phone numbers and expertise on hand at any time.

One thing I need from someone of the forums possibly, would be ecm wiring diagrams of all essential wiring harnesses for both the CVT sport hatch and MT sport hatch 2018.

 

[jtrader]

Wow, so you're actually doing it!?!? Good luck and keep us posted, there will be many people interested in this thread. You'll be a superstar to us CVT guys. Btw, is that a clear glass fridge...in your garage!?!?? ?

 

[Nickthewaffler]

Day 3: Got some more basic work done, didn't have much time but did what I could within a couple hours. Brought my air tools to get the axle nut off and pulled the cv and mid shafts. Turns out the CVT has completely different thickness, which was expected, but still surprised me a little. I ordered Si cv half shafts for both sides for around $250 OEM factory from dealer site. Removed the ecu and most of the electronics brackets on the driver side of the car, keeping the fuse box in for now. Downpipe, frontpipe, midbrace, motor mount all came out today. Planning on dropping the tranny tomorrow, but I'm probably going to have to remove the subframe, I just can't seem to get the starter off without doing so. Played around with clutch pedal positioning and more, just procrastinating until I get the energy to pull out the harder stuff. Key programmer arrived today so I'm now just waiting on ecm to show up, supposed be shipped tomorrow, I really hope so, because it's a make it break it component. If it fails, I may consider learning to custom program an external ecu and ditch the immobilizer, thought that would take a little while, but it honestly sounds like fun if it doesn't cost too much.

So far this has been fun, I always wanted to pull apart everything in sight on this civic like I am doing. I might even remove the radiator hoses for the hell of it. I'm trying to apply a relaxed attitude to this project and take more off than I need to, rather than to try to cram tools in tight clearances. So far no stress, but I can only hope it stays this way.

Still waiting on wiring diagrams from someone who has access to them. If one of yall own an alldata or something dm me asap! Anyway enjoy some pics!

 

[Gruber]

Still confused why the power steering pumps are different from CVT to MT, but hopefully it's nothing too bad, the pumps are discontinued so I need to find a used one if that's the case.

So did you finally find a suitable power steering pump? And don't forget a couple gallons of power steering fluid.

 

[IronFusion]

When you drop the CVT and have the MT, can you evaluate if an LSD mod to the CVT is possible? Something between eyeballing and attempting? Pretty-please?

If my CVT dies, I will be replacing it with another. But, I've always been interested if an Si or aftermarket LSD could be worked in.

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