Frame Angle

1. Frame angle is the degree of tilt in frame from a level position. To determine frame angle, position vehicle on smooth, level surface. Using inclinometer or bubble protractor, measure frame angle. Determine if frame angle is up-in-rear or down-in-rear.
2. To determine corrected caster reading with various frame angles and caster readings apply one of the following rules:
   • Down-in-rear frame angle must be subtracted from a positive caster reading.
   • Up-in-rear frame angle must be added to a positive caster reading.
   • Down-in-rear frame angle must be added to a negative caster reading.
   • Up-in-rear frame angle must be subtracted from a negative caster reading.

If corrected caster or camber is not within specification, go to adjustment procedure.