Ease of use a priority

The AJ0 transmission stands out through its smooth operation, ease of use and silky gear changes which have been obtained thanks to a control unit which constantly analyses parameters such as vehicle speed, engine speed, torque, pedal position, etc. to select the ideal gear. This control unit communicates permanently with the engine control unit to maintain optimal torque during gear changes.

In automatic mode, the control unit selects the ideal gear using auto-adaptive settings based on three parameters - driving style, road type (uphill, downhill, flat) and the driver's real-time reactions - to favour fluidity and smoothness without compromizing either punch or acceleration pick-up.

The control unit is also programmed to downshift instantly if the driver presses hard on the throttle pedal (kick down function) in order to provide extra power when overtaking.

In manual mode, it is the driver who chooses his or her own driving style thanks to the flick-shift lever. This mode notably comes into its own in the case of a dynamic style, for example, or along mountain roads. It also incorporates a number of automatic functions designed to facilitate driving (automatic selection of first gear when the car comes to a standstill) and to protect the gearbox (protection against over-revving).


A modern concept

To favour driveability and fuel efficiency, particular care has gone into the gearshift quality of this cablecontrolled, three-shaft transmission, as well as into minimizing mechanical friction. The system comprises three epicyclic gear trains plus five sets of brakes and clutches. Brake discs have been preferred to brake bands for enhanced shift quality whatever the gear and whether upshifting or downshifting.

An especially welcome feature when motoring around town is the disengagement of the transmission when at a standstill with a view to reducing creep and thereby minimizing residual vibrations and fuel consumption. Meanwhile, the active slip function developed for this transmission has resulted in a significant reduction in the phenomenon of booming at low revs for enhanced driving comfort, notably when re-accelerating.

Compared with four- and five-speed automatic transmissions, this gearbox has two principal benefits: the shorter first gear improves acceleration from standstill, while the longer sixth gear reduces noise when travelling on motorways.

Special attention has been paid to this transmission's acoustic performance, while booming, growl and whine have all been reduced to the strictest minimum thanks to the design of the casing and the hydraulic converter damping system.

Thanks to its pressure-cast aluminium alloy casing, the AJ0 transmission tips the scales at a low 93kg (without fluids). Its compact dimensions (length: 385mm) permit the powertrain to be positioned transversely in the engine compartment. The transmission is lubricated for life by 8 litres of oil and is water-cooled by a circuit incorporated in the casing. It can be mated with both diesel and petrol engines and is predisposed for use with an all-wheel drive vehicle as well as for a high torque capacity variant.

The AJ0 transmission is built at JATCO's Yagi factory in Japan.


Quality - a priority aspect of "Renault Commitment 2009"

Three demonstrators set up on Renault's stand at the Paris Motor Show will give visitors a chance to experience for themselves the notion of quality, a field which the company has earmarked as a priority aspect of "Renault Commitment 2009". This plan targets the positioning of Laguna 3 amongst the top-three cars of its segment in terms of both product and service quality.

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