Land Rover will demonstrate the world’s first 9-speed transmission for a passenger car at the Geneva Motor Show next week. Developed by ZF, in partnership with Land Rover, the ZF 9HP transmission was designed for transverse applications and is one of the most efficient and technically advanced transmissions ever used in a production vehicle.
The Land Rover ZF 9HP gearbox benefits from the increase in the number of gear ratios from six to nine which helps reduce emissions and improves efficiency and response during acceleration while also improving shift quality and refinement.
The ZF 9HP transmission is 6mm longer and weighs 7.5kg less than the outgoing six-speed transmission. The compact packaging is accomplished by using a number of innovative design features such as a new hydraulic vane-type pump, two patented dog clutches, and a nested gear set.
The lowest ratio in the ZF 9HP is lower than the existing six-speed transmission and is designed for off-road use, towing and on-road conditions like steep gradients.
Other benefits include an adaptive shift system that matches and ‘remembers’ customer driving style for a tailored driving experience and a skip-shift function for speedy down shifting to meet rapid deceleration demands.
The Fast-Off mode measures the rate of throttle release and anticipates further requests by the driver for high power and then holds the gear if necessary. Additionally, the torque converter incorporates a multi-stage damper system for smoother pull-away and improved refinement.
Land Rover and ZF have jointly developed transmission solutions for the Range Rover, Land Rover LR4 and Range Rover Sport. The new 9-speed transmission will be produced at ZF’s Grey Court facility in South Carolina, USA.