Ferrari - 456 GTA: the Transmission

Transmission

The general layout of the car is classical, with front mounted engine and driven rear wheels. For good weight distribution the transmission is arranged at the rear in unit with the differential (transaxle).
The single plate clutch is mounted on the flywheel and has hydraulic control. It is equipped with asbestos-free friction material. Power is transmitted from the clutch to the gearbox by means of a propellor shaft supported by three bearings and housed in a steel tube which is rigidly connected to both the engine and the gearbox.

In the 456 GT version, the transmission has six forward speeds all synchronised by double cone synchros, plus reverse. Sixth gear is direct drive, in order to reduce frictional losses when the car is being driven in this condition.
The gearbox is equipped with a pressure lubrication system with a pump and oil radiator. The manual transmission is controlled by a classic cast aluminium lever linkage housing, which acts directly on the selector shafts and forks.
The differential is a ZF multi-plate limited slip, whose locking value is different in drive and lift-off.
The transmission on the 456 GTA is equipped with a 4 speed automatic gearbox with electronic management.
The transaxle set-up, borrowed directly from the mechanical version, is unique in its way, and makes it possible to maintain the correct weight distribution almost unchanged.
The choice of four-speed architecture, bearing in mind the electronic logic of gear changing, the superb elasticity of the engine and the special hydraulic converter setting, guarantees the best overall efficiency, and makes the car particularly fast.

Gear ratios:
 
1^st   2.960/1
2^st   1.626/1
3^st   1.000/1
4^st   0.681/1
Rev.2.130/1

Rear axle ratio:

     3.530/1

Gear selection
positions follow
the classic layout:

P:   Parking
R:   Reverse
N:   Neutral
D:   Drive
3:   Third
2:   Second
1:   First