Compared to a hose control, the hydraulic control guarantees automatic adjustment of pedal wear; on the JTD versions, this system is combined with a device that takes up the clutch plate wear so that the load of the clutch pedal remains constant for the car's entire life. To comply with European legislation to protect the environment, all versions, both petrol and diesel, adopt friction materials that only contain environment-friendly elements. And the clutch pump has a plastic body, which helps to lower the weight, a steel cylinder and a plastic piston.


The 5-speed gearbox for the 1.2 8v and 1.4 8v engines

Enhanced acoustic comfort, reduced engagement effort even when cold, and more precise gear engagement. These are the advantages of the C514 gearbox (a transverse configuration with two shafts in a cascade and one differential), which was optimised by changes to: the gears, synchronisers, lubrication, internal gear control and clutch control. Combined with the 5-speed Fire 1.2 8v and 1.4 8v engines, this version represents the maximum upgrade of the gearbox in terms of transmissible torque (15 kgm). The use of nobler materials for the gears, the adoption of a more powerful differential with larger conical gears and the screw connection between the housing and the crown all improve reliability. The main features are excellent manoeuvring of the gear lever, quiet operation and low weight.

What is more, the gearbox adopts a gear control which, thanks to stroke limiter selection, protects against the risk of involuntarily engaging reverse, and makes engagement of fifth and sixth speeds more precise. And finally, the use of gearing made of quality materials and of a completely redesigned differential, made it possible to strengthen the gearbox itself, which in this configuration can transmit up to 15 kgm of torque.

The most significant technical features are the gearing and clutch housings, which were optimised to lower the weight and to absorb noise better, using FEM (Finite Element Method) calculation techniques. Plus Borg-Warner free-ring synchronisation on all gears. And finally, a dual cone synchroniser on first and second, the gears used most frequently, with an engagement effort that is 40% lower than the effort required with a conventional single cone synchroniser.

The internal gear control system has four selection levels, with a central positioner and bearings. Lubrication is dynamic, and the oil flow is channelled through bore holes in the housing. The advantages are less wear and more efficient torque transmission, and manoeuvrability even at low temperatures.


The 5-speed gearbox for the 75 bhp 1.3 Multijet engine

The C510 is extremely easy to manoeuvre and very quiet. It has a transverse configuration with two shafts in a cascade and one differential. In this case too, the gearbox has been optimised, adopting a dual cone synchroniser on first and second, and a highly efficient reverse engagement control. Two improvements that guarantee the product's excellence where manoeuvring is concerned. Lubrication is dynamic and the oil is channelled through bore holes in the housing and on the shafts. The maximum torque transmissible is 21 kgm.

The 6-speed gearbox for the 120 bhp and 130 bhp 1.9 Multijet engine and the 90 bhp 1.3 Multijet

The M20 and M32 gearboxes belong to a new family of three-axis transmissions, designed to give better manoeuvring and to be more compact than traditional two-axis gearboxes. Available with 6 speeds, these two units can support high torque (230 Nm and 320 Nm), so they are the ideal for high performance diesel engines: the 90 bhp 1.3 Multijet (M20) and the 120 bhp and 130 bhp 1.9 Multijet (M32).

In this case too, the engineers' goal was to improve acoustic comfort, to eliminate any vibration or shaking of the gearshift, and to reduce actuation and engagement effort even when the engine is cold. The gearbox (with three shafts and a built-in differential) has small axial measurements, and is easy to manoeuvre in all speeds, and extremely quiet. The credit goes to a number of innovative solutions that were already employed on earlier gearboxes, such as free ring synchronisers, dual-cone synchronisers on first and second, and dynamic lubrication.
 
previous page