Castor angle is the angle the king pins (the 2 pivots the front wheel turns on) lays backwards in relation to the ground. A Land Rover should have 3 degrees. When a vehicle was released from the factory on average had 2 1/2 “ front bump stop and 3 degrees of caster. When fitting higher springs the caster angle is affected. For every ½” a vehicle is raised the castor will decrease by 1 degree.
Caster angle makes the vehicle drive straight, helps return the front wheels to centre after cornering and will keep the steering easy to control at high speeds. A car with a 0 or negative caster angle is very twitchy of the freeway and the driver has to concentrate a lot harder to drive the vehicle increasing driver fatigue.
The steering castor can be corrected in a number of ways and it will depend on what modifications have been done and vehicle you are working with.
A simple solution. Custom made radius arm bushes made to roll the whole housing backwards correcting the caster by 2.6 degrees. This is a cheaper alternative to radius arms and modifying swivels and is also very effective.
Click here to view Castor Bush Options
This is the best way to correct caster angle. The caster angle can be set to any angle once machining has started. By rolling only the swivel housing backwards will not alter any of the diff to prop shaft angles giving the absolute best solution to all problems.