I know I need a new tranny, but anyone ever had this happen?

[jbarxgen]

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[DadBodMod17]

You blew the overflow plug off??

 

[Chris_19Si]

If this is the location of your damaged case, I cannot imagine what it looks like inside. What led up to this?

 

[jbarxgen]

If this is the location of your damaged case, I cannot imagine what it looks like inside. What led up to this?

That’s the thing, I’m not quite sure what led up to it, drove to get some food, parked, ate, came back to reverse out of the spot and it just suddenly stopped and almost got stuck in reverse, had to push it back into the spot because it wouldn’t go into gear. Honestly very strange even my personal mechanic is pretty lost.

 

[jbarxgen]

You blew the overflow plug off??

I think so? I’m not quite sure to be honest. I’ve driven about 40k miles on my new clutch with no issues until this happened, don’t think it has to do with clutch just honestly pretty lost…

 

[Chris_19Si]

The only thing under that plug is the countershaft bearing and snap ring. How much torque are you tuned for, and do you drive the car hard?

 

[Chris_19Si]

Now that I'm more awake and on a PC, I can clearly see the end of the case is blown out, not just the threaded plug. This really begs the question, was this transmission recently rebuilt? I can see how this might happen if the countershaft bearing wasn't captured during reassembly and the case tightened down, then there would be stress on the end of the case for sure.

If you are the original owner and the trans has never been rebuilt, then the countershaft axial load must have been super high to cause this, or there was a flaw in the casting of the case, and it let go possibly due to high cyclic loading.

I have rebuilt a couple of transmissions several times, and the countershaft installed under the snap ring seems the most likely cause. I just can't see how enough axial thrust could be generated to cause this without a flaw already being in the casting of the end of the case.

Depending on how you respond, you might get by with just replacing the transmission side of the case. They are not expensive. If you didn't destroy the internals, and there isn't much aluminum to clean up, this could be an easy fix! You would have to uninstall it from the car of course, but you might get lucky with very minor damage.

 

[jbarxgen]

The only thing under that plug is the countershaft bearing and snap ring. How much torque are you tuned for, and do you drive the car hard?

I have PRL CAI, RV6 performance Catless downpipe and frontpipe and tuned on Ktuner with TSP stage 1 making 229hp 242tq. And I’d say less than more you know, like I do sometimes but very rarely.

 

[jbarxgen]

Now that I'm more awake and on a PC, I can clearly see the end of the case is blown out, not just the threaded plug. This really begs the question, was this transmission recently rebuilt? I can see how this might happen if the countershaft bearing wasn't captured during reassembly and the case tightened down, then there would be stress on the end of the case for sure.

If you are the original owner and the trans has never been rebuilt, then the countershaft axial load must have been super high to cause this, or there was a flaw in the casting of the case, and it let go possibly due to high cyclic loading.

I have rebuilt a couple of transmissions several times, and the countershaft installed under the snap ring seems the most likely cause. I just can't see how enough axial thrust could be generated to cause this without a flaw already being in the casting of the end of the case.

Depending on how you respond, you might get by with just replacing the transmission side of the case. They are not expensive. If you didn't destroy the internals, and there isn't much aluminum to clean up, this could be an easy fix! You would have to uninstall it from the car of course, but you might get lucky with very minor damage.

Transmission has never been rebuilt, just replaced clutch with RV6 retrofit FK8 flywheel with oem FK8 pressure plate. Been driving on that setup for about 40k miles and absolutely loving it. And I’m not to sure what I’m gonna do yet, my friend who works at Honda is gonna see what they can do.

 

[Chris_19Si]

With the countershaft bearing completely exposed, the shaft probably walks in and out and binds with the mainshaft. Hopefully your Honda buddy can offer you a deal on new one, or help you find and replace it with a good used one. They are quite expensive new, and $1,200 - a lot for a used one. I'd keep the old one and rip it apart to look for a cheap repair, then keep it as a spare, or rebuild with upgraded gears. If you intend to bang on it, definitely upgrade the spare and swap it back in, while keeping the good one as the new spare. This was my strategy until I upgraded both of mine. Who would have thought you'd need a spare transmission for a Civic!

 

[ManitobaSI]

Hey. Looking closely at the photo it’s not just the plug blown off. It’s the whole end where the mainshaft is. The plug looks like a secondary issue. The issues might be the thrust was too tight and the main shim was too big from the factory. This is what happens when shims are too big. If main shaft thrust was out of spec then it should be covered under warranty.

 

[jbarxgen]

With the countershaft bearing completely exposed, the shaft probably walks in and out and binds with the mainshaft. Hopefully your Honda buddy can offer you a deal on new one, or help you find and replace it with a good used one. They are quite expensive new, and $1,200 - a lot for a used one. I'd keep the old one and rip it apart to look for a cheap repair, then keep it as a spare, or rebuild with upgraded gears. If you intend to bang on it, definitely upgrade the spare and swap it back in, while keeping the good one as the new spare. This was my strategy until I upgraded both of mine. Who would have thought you'd need a spare transmission for a Civic!

Yeah, we are searching for a used transmission for a quick fix, then build the spare like you said! Might be a dumb question but is coupe and sedan transmission the same?

 

[Chris_19Si]

I believe they are, but best to confirm with Honda. Might also try the online parts stores and just look at the two case halves for the same part numbers between the two cars. Might be that easy. If the case halves are the same, the internals should also be the same. Perhaps the forum could confirm this in parallel with your research.

 

[KensBlueGenX]

is coupe and sedan transmission the same?

Not an Si, correct? Then yes, any of them will go in.

BTW, the only dumb question is an un-asked question!

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