** All OS Giken products are available to order, as per OS Giken distribution rules they are 4-6 week lead time to order in from Japan. Please contact us with any quesitons **

Are you doing that needed clutch or trans rebuild on your Alfa for the upcoming race season? Be sure and do it to last with our OS Giken parts. Time tested quality on a wide range of Alfa Romeos, these are built to withstand power upgrades and race track use. Quality in every cut and detail of the metal and 100% made in Japan.

Limited Slip Differential:
OS Giken uses the proven plate type system for the best power delivery available to Bertone 105/115 GTV owners. With industry leading 28 clutch plates in each differential, action is smooth and consistent. The extra plates make the action more reliable and smoother than any other plate type diff, geared helical diff, or gripper diff on the market. Patented “Super Lock LSD” technology is able to achieve complete lock in a progressive, smooth, and quiet manner. This translates to quick lap times and repeatable tuning and performance. Tested and trusted on tracks around the world, this is the perfect way to keep the power down in your fast Alfa.

Clutch kits:
The clutches are able to withstand a substantial increase in power yet remain easy on the foot. The billet aluminum cover saves weight while providing a more direct clutch pedal feel, but still maintains ease of engagement due to the unique leverage mechanism of the diaphragm spring. Available for GTV, GTA, Spider, Berlina, Giulia & Alfetta. Both single and twin plate versions depending on application and engine torque output. All clutch kits are hydraulic type, if cable style is needed please inquire.

Transmission Short Ratio Gear kits: ** Update - OS Giken Alfa close ratio kits are discontinued and no longer available.