wildmanbaker wrote:
Wes Tausend wrote:
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Some thoughts on suspension...
I like the descriptive phrase of "saw steering" that Mark (427435) brought up. Good way put it.
The F-53, with an I-beam axle, must be similar to smaller, older 4X4 trucks with a live front axle..........
...........Increasing sway bar tension can also cover up a problem with bump-steer if it exists. Bump-steer is a condition whereby the toe-in changes with suspension spring compression/decompression. This appears when the truck leans during a sway maneuver and the spring compression change affects geometry of the steering tie-rod, which in turn pulls the toe-in setting out of alignment. This can cause a darting reaction that makes the sway escalate much worse and demands a frantic correction, or series of corrections, from the driver as though he is walking a tightrope. Very tiring and worse, hard to intuitively recognize the precise root source from steering feel. The truck just plain steers bad, that is the unsophisticated overall feeling.
Wes
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What? Apples to oranges.... Bump-steer with a I bean axle? You probably have a usable though, but I am having trouble sorting it out.
wildmanbaker,
Good catch. You are quite correct that classical "toe-in" bump-steer will not occur with a solid I-Beam axle. I started to speak in general terms, but should have left it out of this discussion.
Bump-steer doesn't normally occur on a 4X4 F-250 either for example, because there is a single tie-rod from spindle-to-spindle and we could assume this is also true of the F-53 (Of note, F-250-350 4X4's use a pan-hard bar). Some very minor steering variation may take place during bump (spring compression) in that the drag link swings in an arc rather than perfectly moving vertically.
True bump-steer could more easily occur on an independently sprung smaller twin-I-beam 2wd truck though, since the tie rod is split. I'm not sure if some F-350 mini-homes use the twin-I-beam. Bump-steer should not be a major problem for either drive configuration unless some smaller truck is jacked up for off-road, with an extreme drag link angle.
Wes
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