Steering (Steering column): Description and operation (page 2 of 2)

When the lever is lowered the nut is slackened and allows the column to be moved up or down to the desired position. Lifting the lever upwards tightens the nut, clamping the mounting bracket to the column, retaining the steering column in the selected position.

NOTE: The nut tightening torque is 10.5 Nm which gives the correct ’feel’ to the lever operation.

The steering lock houses the ignition switch, ignition illumination light ring, key lock barrel and the alarm passive coil

The steering lock is attached to the upper column with a clamp plate and two shear bolts. The bolts are tightened to a torque which shears off the heads of the bolts preventing easy removal of the steering lock.

The steering lock operates by a bolt, which emerges when the ignition key is turned to position ’O’ and the ignition key removed. The bolt engages in a lock collar located on the upper shaft in the upper column tube. The lock collar is attached to the upper shaft by a ’wave form’ interference ring. The lock collar is allowed to slip on the upper shaft if a torque of 200 Nm or higher is applied. This prevents damage to the steering lock, yet still prevents the vehicle from being driven.

The steering lock is designed to be resistant to slide hammer, shock retraction and scaffold pole attack and cannot be damaged by torque transmitted through the column.