Workshop Manuals Factory service & repair Vauxhall
Vauxhall Astra H07 · Rear Axle and Rear Wheel Suspension
07 · Steering & suspension

Rear Axle and Rear Wheel Suspension (Castor): Repair Instructions

Make
Vauxhall
Model
Astra H
Section
Repair Instructions › Castor
Rear Axle and Rear Wheel SuspensionCastor

Castor

Castor is the angle produced between the line running through the steering axis (2) in the direction of the axis of symmetry and a vertical line (1) through the wheel centre to the road.

The castor is negative if the point of intersection of this imaginary line with the plane of the road is behind the wheel contact point. It is positive if it is in front of the wheel contact point.

A positively adjusted castor pulls the wheels which helps to restore the wheels to the straight-ahead position after cornering.

 Object Number: 2400756 Size: DEFAULT

Effects of incorrect measurement angles

Castor too negative:

  • poor steering return
  • susceptibility to tyre faults (conicity, angle effect)
  • can lead to skewing
  • wheel wobble
  • sensitivity to side winds

Castor too positive:

  • high steering and holding forces

Castor different left to right:

  • susceptibility to skewing

Parts & tools for this job For Vauxhall Astra

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