Steering Column - Sectional View

The column comprises a cast magnesium mounting bracket which provides the attachment to the cross-beam. Attached to the mounting bracket is a rake lever which is attached to the mounting bracket at the lower end with two pivot bearings. The bearings allow the rake lever to rotate upwards or downward to adjust the column rake.

The rake lever also provides for the attachment of the rake housing which can slide within the lever to provide the reach adjustment. Within the rake housing is the axial housing which is supported on each side with 6 ball bearings which allow the rake housing to move forward or backwards. The bearings on each side are arranged in groups of 3 bearings and are separated by a distance keeper which allows the housing to supported on bearings along its length. Within the axial housing is a tube which is supported at the upper end of the column on the upper bearing. The tube has a central splined hole which provides for the fitment of the splined shaft. The splined shaft can slide within the tube on the splines when the column reach is adjusted or the column collapses in a crash condition. The splined shaft also passes rotary motion from the steering wheel through the length of the column to the outer clamping yoke which is supported on the lower bearing.

The electric steering column lock is attached to the top of the rake lever. A lock bolt within the steering column lock engages in one of 8 slots in the locking sleeve located at the lower end of the column preventing rotation of the steering wheel. The locking sleeve is retained by a tolerance ring which in turn is located on the outer diameter of the tube yoke. The tolerance ring allows a specified amount of torque to be applied to the splined shaft before it slips, preventing damage to the column lock due to excessive force being applied to the steering wheel when the lock is engaged. The tolerance ring is designed to slip on the splined shaft when the applied torque exceeds the fitted slip load of 200 Nm minimum. Repeated rotation of the lock collar will reduce its slipping torque to 100 Nm minimum. The lock is controlled by the CJB.

A steering angle sensor is located at the upper end of the steering column and is attached to the crash adaptor. The sensor measures steering rotation via a toothed wheel located on the splined tube at the upper end of the column. The sensor receives a power supply from the CJB and supplies 2 signals (A and B) relating to the steering rotation to the ABS (anti-lock brake system) module. The module transmits this data on the high speed CAN bus for use by other vehicle systems.

Refer to Anti-Lock Control - Stability Assist (Description and Operation).

The steering column is adjustable electrically, for reach and rake. The adjustment mechanism comprises an electric adjustment motor, a lead screw, a rake solenoid, a reach solenoid, a reach clutch and a rake clutch. The column adjustment is controlled manually using a joystick switch located on the LH (left-hand) side of the column lower cowl. The joystick can be moved forward and backward to adjust the column reach in and out and moved up and down to adjust the rake. The switch selection energizes the adjustment motor in the applicable direction and also engages the applicable solenoid and clutch.

When the joystick switch is rotated to the 'auto' position, the steering column will adjust to the uppermost rake position when the ignition is switched off. It will re-adjust to the position corresponding to the memory position for the remote handset when the ignition is switched on.

The memory function of the electric column is linked to and controlled by the driver's seat module. The module provides for the storage of three separate memory positions which are stored against 3 individual remote handsets.

Refer to Seats - Component Location (G1526739) (Description and Operation).

The steering wheel locates on a splined shaft in the upper column assembly and is secured with a bolt. The steering wheel houses the driver's airbag and switches for the audio system, gear change and speed control. A clockspring is used to connect the steering wheel electrical components to the vehicle harness.

Two plastic shrouds are fitted to the upper column assembly. The lower shroud is fitted with an energy absorbing foam pad to minimize leg injury in the event of an accident.