B18C1 Y80 Transmission Rebuild - Import Tuner Magazine

I'll never forget test-driving my first newly swapped Civic years ago. No matter how effectively the preceding week of mind-racking stress of installing that '94 B18C1 GSR engine and trans into my '95 Civic DX taxes the memory, I can recall the moments as if they happened yesterday: the foreign sound of the new starter cranking the dual-cam engine to life, the increased NVH levels felt at idle, and the massive power and gearing improvements the new combination delivered over the previous D15 arrangement. I can also remember shifting into Third Gear for the first time-the moment my unadulterated bliss was traded for an emotion felt by anyone the moment they realize they're f*cked-which can only be described in one onomatopoeiatic offering: "grreeacchhhkk!"

1 So that we could document the rebuild without getting our gear greasy (not that it already isn't), we decided to let Synchrotech's techs handle the process while we followed. Transmission rebuilding can seem like a daunting task, but with a factory service manual (FSM-available at any Honda dealership, or online at: estore.honda.com) kept on hand, mechanically inclined gearheads of any experience level should have no problem. Step one: remove the release fork and boot, throwout bearing, and everything else from the clutch housing.

1 So that we could document the rebuild without getting our gear greasy (not that it alre

"What the hell was that?!" I asked my shotgun-riding, seasoned vet of the wrench.

"That's the sound of a worn synchro," he responded.

"OK . . . what can I do about it?"

"Nothing. Replace the transmission and hope it doesn't happen again."

Fortunately, times have changed.
When the same problem surfaced in Project DC2 a little while back-on the up-shift from Third to Fourth-we decided it was time to find a permanent solution. We had two options: we could replace the trans with a nicer-looking one from a junkyard and hope for the best, or we could spent a small fortune on a complete synchro and sleeve set from a Honda dealership (synchros/sleeves aren't sold individually), re-build our trans to OE specs and hope it lasts a decent amount of time before it starts grinding again. It wasn't until we caught up with Synchrotech in San Dimas, CA, that we learned of a third option: order only the components we need (at manufacturer-direct costs), and rebuild the trans ourselves or have them do it for a nominal fee. We could even upgrade our OEM brass synchros to their proprietary carbon-coated or full carbon-fiber synchros to increase performance and longevity, and still save coin in the process. Turns out our choice really wasn't one after all.

2 Next, remove the speed sensor, reverse light sensor assembly and stay, both metal hangers, and breather cap from the transmission housing.
2 Next, remove the speed sensor, reverse light sensor assembly and stay, both metal hange
2, cont.
2, cont.

2, cont.
2, cont.
3 The drain and fill plugs are next to go.

3, cont.
4 Now you're ready to remove the 12mm bolts joining the transmission housing to the clutch housing.
4 Now you're ready to remove the 12mm bolts joining the transmission housing to the clutc
5 Before you can separate the two housings of the transmission, you'll need to remove the hex-head sealing bolt and square-head sealing screw at the end of the transmission housing, to access the snap-ring that locks onto the countershaft.
5 Before you can separate the two housings of the transmission, you'll need to remove the