Today saw me fit the steering rack to the mounting points on the chassis. GD supplies the rack with split polyurethane bushes which which just pop straight on and are then bolted down using a couple of packing washers. The track rod ends are screwed on and inserted into the supplied steering arms. Once the rack was fitted it needed to be centred.
Centring of the rack is achieved by marking the input shaft and using masking tape marking a datum point on the steering rack. Counting the number of turns from full right lock, marking and then returning to full left lock and again marking it. Finally, turn the rack back to 1⁄2 the number of turns between the two marks.
Next was to set the “toe in” by clamping a 1m piece of angle to each disc face and measuring both front and rear then subtracting the rear measurement from the front which provides the “toe in/out” calculation.
The Gardner Douglas manual recommends 0.0mm to 1.5mm “toe in” maximum which is achieved by winding the track rods in (or out) until the required measurement is obtained.
Having achieved the the correct “toe in”, it was time to validate the alignment of the wheels using the 1m angle clamped to the centreline of the chassis (as marked when setting the rear axle). With the laser level clamped to the disc I marked the red dot on the angle, then repeated it on the other side. I then measured the distance between the two marked points and marked the centre of that on the angle. I then moved the angle so the centrelines on the angle and the chassis corresponded and adjusted the track rods until the laser came back to the marks made on the angle. Now we have all wheels pointing in the right direction.