Turn the wheels full left and right and measure the camber change at each
position. The caster is 1/2 the difference if the wheels had turned to 90
degrees so you have to do some calculation there. Since you have one that
hasn't been changed, you can compare between the two sides and make them
equal. It is more important to have matched caster than an absolute value.

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Why isn't there an Ozone Hole at the NORTH Pole?