A diamond-like carbon (DLC) coating has been developed for the transmission gears to increase their transmission efficiency. Using the carbon sputter method increased topcoat hardness and suppressed the formation of interfaces within the coating film, which enhanced durability under high surface pressures. This DLC was applied to the shift gear, final gear and bevel gear, and contributed to reducing friction. In addition, it secured the reliability needed to enable continuous use in the 4-Race events that Formula One regulations prescribe.
Article of Honda R&D Technical Review F1 Special (The third Era Activities) (276 - 277)