Hyudryu

Hi guys,

K24Z6 9th gen civic SI 6 speed manual. I purchased a set of gearx 1-4 reinforced gears, and I installed it two weeks ago. The kit came with a new mainshaft, 3rd 4th gears, and all the corresponding countershaft gears.
Long story short, I removed oem gears, pressed the new ones in, closed it up and it shifted great. Drove great too.... until one day. As I was reversing out of a parking spot, the transmission got stuck. Clutching in, the car wouldn't roll at all. My friend who's a mechanic came to help me out. We rocked the car back and forth and pulled in the shift lever and got it back into "neutral" but was still unable to push it because it was still stuck in a gear. After wiggling it around in neutral, we shifted into the stuck gear (which appeared to be 2nd) and when we shifted out, it "unstuck" the transmission. So I tried drivingit again, and it popped out of first when i give it some gas...

Fast forward a week, and here we are today. We just got the transmission out, and tore it apart once again. We took some notes on the gear "smoothness" before we took apart the casing. We found that 2nd and 5th gear were really hard to turn, and reverse was almost impossible to turn (turning the shaft). Anyways, we ripped apart the transmission and this is what we found:
Countershaft bolt was loose when I removed the case today. We torqued it to 80 something ft/lb as it said on the manual prior to reassembly(from before), so not sure why it was loose. Also noticed that it was scraping against the transmission case, so that bolt was shaving pieces of aluminum off of the casing.

Gears aren't perfectly aligned...

I'm not sure why the countershaft bolt even came off. I'm guessing that the rotation of the shaft caused the bolt to loosen up and press against the case, and that created more and more pressure. Could that be the reason why my transmission locked up? Should I just threadlock that bolt and throw it back on the car?


Thanks,
Mark

Aquafina

iTrader: (3)

That isn't the correct torque spec for the bolt, what manual are you using? The gear alignment will be off without the case on and snap ring seated.

Did you shim the mainshaft and countershaft or just drop them in? They need to be shimmed.

Hyudryu

My friend works at honda, and he got me a copy of the PDF for countershaft and mainshaft disassembly, and reassembly. On the shop manual, it said to torque it to 87 ft/lb. I reused all the factory shims, and I actually fixed the issue last week. The bearing on the countershaft came outwards after the bolt came loose, so there was a big 1-2mm gap between 6th gear and the bearing. Luckily, nothing broke and I pressed the bearing back with a 0.04mm clearance between the shim and the bearing, applied plenty of threadlock red to the bolt, and tightened it down real good. So far, tranny shifts like butter, and seems to be holding great