I'm not familar with the term "cross fall" but I am guessing that it is the point of transistion at which a lift would be traveling from a level warehouse floor on to a down ramp. If my guess is correct then on a lift truck this would be referred to as the "break over angle" (at least in the States or at that is what I learned along the way). This angle varies wideley from model to model & make to make due to several key factors - wheelbase ground clearance distancebewteen the wheelbase points (most often this is the frame side members, but I have seen oldr model Toyota's where the transmission actually was below the frame) and some units had metal ring protector welded around a hydraulic or fuel tank drain plug. But what ever is the lowest point is what we need to be concerned with.
The break over angle is formed by two line one starting a point wher the steer tire contactct the ground adn the other where the drive tire contact the ground. Then a line is drawn upwards towards the midpoint of the wheelbase and where the intersect at the lowest point an angle are created - this is the break over angle of the lift truck (and after all these words hopefully the "cross fall" angle). At one time most lift truck companies in the US published this info (I did when I was involved in literature development) but more & more companies now follow the ISO formats on there specification literature. But manufactuers can supply this info w/o much issue - unless they are too busy or sleeping.
One final note, this angle will vary as the tires wear (the lowest point gets closer to the ground) and the steering tires generally wear out twice as fast as the drive. So it is always best to use the data on the conservative side.
If I have totally confused you send me a mailing address & I'll draw you my best stick picture w/ real stick men with a straight edge & a dime (or a 6 pence) and forward it.