74187 - Specifications

The steering system is equipped with a telescopic type steering column and power assisted steering on all versions.This type of system guarantees:

  • steering precision and safety at high speed
  • good handling
  • limited effort required for parking manoeuvres and at low speed.

STEERING COLUMN ADJUSTMENT

By using the special electrical control (joystick) located on the left side of the plastic steering column casing it is possible to carry out longitudinal (± 20 mm) and rocker adjustments with a vertical adjustment (1°, 30' upwards and 2° downwards). The steering column consists of two sections which greatly increases the safety of the driver, preventing the steering wheel from moving back dangerously in the case of a frontal impact.The upper part of the steering column houses the ignition switch Description and operation [5520A] IGNITION SWITCH which contains the steering lock and the LANCIA CODE control unit aerial (See assembly ) 5580E ANTI-THEFT DEVICE The steering column is also equipped with a "friction" type steering lock, as required by anti-theft regulations, which intervenes each time the ignition key is extracted from the ignition.The centre section of the steering column houses the two electric motors for moving it which receive a 12V supply.
If the supply polarity is reversed, the system would not work properly and the adjustments would be clearly wrong.
If one of the motors is not working, it would not be possible to carry out the adjustment; if the problem is located in one of the two motors then the complete steering column should be replaced.The vehicles are also equipped with Easy Entry, the adjustment of the steering column is linked to the left front driver's seat and to the rear view mirrors, managed by a specific control unit.The steering wheel features a high passive safety specification and contains the Air Bag (See assembly ) 5580C AIR BAG SYSTEM The steering column switch unit is located between the steering wheel fastening and the steering column and houses the following:

  • The clock spring
  • Steering angle sensor
The steering angle sensor cannot be replaced individually, therefore if there is a problem it should be replaced together with the steering column switch unit.The two steering angle sensor microprocessors are located on the steering column switch unit.One of the two microprocessors is always in an active or checking state even with the key in the OFF position. This is in case the steering wheel is moved with the vehicle stationary (key in off position). The control microprocessor records the change in movement in order to ensure the correct operation of the vehicle when a key-on is carried out.If one of the two microprocessors is faulty, the ESP system is deactivated.If the battery is disconnected, the steering angle sensor's memory is lost and the self-learning procedure has to be carried out.This must be carried out as follows:

  • Reconnect the battery
  • Start up the engine
  • Rotate the steering wheel slightly (about 18°) in each direction
  • Move the vehicle several metres at a speed of below 3 Km/h
At this point the ESP sensor notifies the steering angle sensor of a position of 0°, then the sensor proceeds with calibrating itself.The steering box, which is extremely robust, has a rack and oversize rods to limit flexible yielding of the steering line and guarantees excellent driving precision.

steering control

CONSTRUCTION SPECIFICATIONS

The steering column consists of:

  • collapsible cover lower section which makes it possible to keep the position of the steering wheel fixed in the case of a frontal impact;
  • upper section sustained by a magnesium support secured, in turn, to a steel bracket.
Thanks to their high rigidity these components make a considerable contribution to keeping down the steering wheel vibrations with the advantage of improved driving comfort.There is a friction device on the upper section of the steering wheel which consists of a bush and a spring and has a smooth outer surface and a toothed inside known as a Rencol ring. The toothed section is a press fit on the upper shaft and cuts into the surface slightly thereby forming one piece with the actual shaft. The smooth part is a press fit on the inner diameter of the bush and can slide, by rotating, in relation to the actual bush with a torque of between 10 and 24 daNm.In the case of a theft attempt the function of the friction system guarantees the following:

  • the security of the steering column;
  • the impossibility of breaking the lock mechanism.

STEERING LINKAGE

The steering rods have a flexible element which has the function of damping the vibrations due to the kinematic motion of the suspension and of eliminating the vibrations, transmitted to the steering wheel, in the various steering conditions.

POWER STEERING HYDRAULIC SYSTEM

The power assisted steering system is operated by an aluminium pump which, in addition to being light (the effort at the steering wheel is 4 Nm when steering in a stationary position), is extremely quiet when it is working. The system has also been designed to keep hydraulic pulses which sometimes produce noise to a minimum.The choice of calibration has been made to achieve a constant balance between light steering when stationary and road holding when driving at speed.
The steering box has been designed with oversize rods and rack capable of absorbing considerable stress in order to limit flexible yielding of the steering line as far as possible and thereby guarantee precise driving.To avoid water and dirt entering and to limit noise in the area in contact with the bodyshell there is an insulating buffer which, pressed against the panel, produces a sealing action.The ratio of the steering box is 68 mm / turn which corresponds to 2.2 turns of the steering wheel with a turning circle of 11.5.
The hydraulic power assisted steering system has an aluminium pump which greatly contributes to quiet operation.The following solutions used for the system also contribute to quiet operation:

  • high pressure fluid pipes of optimum shape and length with internal resonators which dampen the fluid pulsations;
  • a cooling coil to keep the temperature of the power assisted steering fluid low and prevent cavitation.
The fluid reservoir is located on the left of the upper engine shield by the power assisted steering pump. There is a filter inside the reservoir which traps impurities larger than 100 micron.