Originally Posted by Lonnieb
That's greek to me. They hooked it up to machine/computer and it was within tolerance, at least that what they said.
The specified caster tolerance for the E350/E450 cutaways is about +1.5 to +7 degrees.
Ford ships all E350/E450 cut aways with identical fixed, non adjustable
caster/camber collars, "one size fits all". You can recognize these collars because they are keyed and cannot be rotated. They are marked "F8UA-AA 0+.25" on the passenger side and "E97A-CA +0-0" on the drivers side.
The RV builder almost never changes the Ford collars, as a result:
If the final RV build is nose down one degree then the runtime caster will be about +3.5 degrees. These units can have a real wandering problem.
If the final RV build is nose level then the runtime caster will be about +4.5 degrees. These units are probably indifferent.
If the final RV build is nose up one degree then the runtime caster will be about +5.5 degrees. These units are probably just fine, possibly excepting the 31+ footers.
So, some RVs have a problem with wandering at highway speeds and some do not have a problem. JMO.
POPULAR MECHANICS MAY 1973:
If too little caster exists, the car will wander and weave,
thus necessitating constant corrections in steering.