How do you measure caster split?

[jtison]

The Ford Service manual for the Explorer gives specs for a "caster split" as a negative degree value of -0.8 degrees, plus or minus 0.4 degrees.

When the split is negative, which side is supposed to be greater than the other? Another way of putting this is "which side do you subtract from the other to determine caster split?".

My L caster is +5.4375 degrees, and my R caster is +4.8750 degrees. The difference between the two is 0.5625 degrees. Am I within spec or not?

Anybody know?

TIA,
--Jim--

 

[omegaman2]

It's been awhile since I've done alignments but I would say you within specs. O cars where the caster was easy to adjust (unlike explorers) we used to have less caster on the left side (drivers) of the car to compensate for pulling due to road crown so on your car the measurements would be reversed left to right!