Wheels and Tyres Steering/Wheel Alignment

HarryMann: Steering/Wheel Alignment sign conventions and notes

See [Steering Geometry/Alignment| Steering geometry/alignment] for more detailed information...

Camber +ve Should be top of wheel leaning out c.f. bottom

Caster + ve The steering axis of left front wheel slopes from bottom left to top right; right front wheel, from bottom right to top left. This would usually be the angle of a Maccy strut or the angle between the upper and lower ball joints; the actual point of contact Vs the camberline is not taken into account, just the angle, whether it leads or trails

Toe +ve Toeing-in. For front: Toe-in sensitises the steering and toe-out de-sensitises it (e.g. whitelining) This due to the ackerman steering geometry, if you think about it.

Then there's SAI (Steering Axis inclination), like caster but viewed from the front.

Scrub Radius/Kingpin Offset - preset. VW were early adopters of -ve scrub radius (allowing you to be totally unaware of a tyre going flat - great!)

Note: The slope of whole van, front to rear can affect caster, but is usually not adjustable. Heavy slope has more effect on roll-centres than caster, with regard to handling (witness overloaded Paddy Pickups swaying all over the road, also contributed to by under-inflated rears Vs fronts, for the load carried - Grandma, Grandad, 8 kids and 3 tons of knocked-off sand and cement)