The new Hyundai 8 speed automatic transmission has improved fuel economy by an impressive 7.3% when compared with the existing 6-speed automatic transmission unit and will arrive to Hyundai & Kia FWD models suchs as new K7, Aslan and the future Grandeur.
The new transmission is based on a unique layout, with an additional clutch to Hyundai Motor’s 6-speed automatic transmission. By increasing the gear span with a more number of gears, the transmission comes with an improved acceleration performance at the low gear range, and enhanced fuel economy and NVH at the high gear range. Even with all these improvements, the weight has also been reduced by 3.5 kg from the 6-speed automatic transmission.
The unit’s gains in economy and performance come from several sources including a direct control valve body that allows solenoid control of the clutch directly rather than via several valves. By simplifying the structure of the valve body, the new transmission reduces oil leakage and improves the stability of gear shifting.
Other optimized parts include a re-engineered oil pump. This integral component may reduce the power of most auto transmissions, so the company improved efficiency of the 8-speed automatic transmission by optimizing the teeth and reducing the size of the pump gearing.
A separate system to control the 4-disc damper clutch, instead of a single disc, allows the enlargement of the lock-up range and faster response for damper control.
The new transmission also features a three-pronged approach to friction loss, ultimately boosting economy. The groove patterns are engineered to optimize the clutch for low drag, while a refined baffle plate minimizes the churning losses of transmission oil. Finally, demonstrating the attention to detail in engineering, the ball bearing contact areas have been reduced between rolling elements to help boost the powertrain’s efficiency.